PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED AUGUST 2, 1996
 
LOGO                             $250,000,000
 
                                UNUM CORPORATION
 
                          MEDIUM-TERM NOTES, SERIES C
                    DUE 9 MONTHS OR MORE FROM DATE OF ISSUE
                                 --------------
 
    The Company may offer from time to time its Medium-Term Notes, Series C (the
"Notes"), due from 9 months or more from the date of issue, as selected by the
purchaser and agreed to by the Company, at an aggregate initial public offering
price not to exceed $250,000,000 or its equivalent in foreign currencies,
currency units or composite currencies.
 
    The Notes may be denominated in U.S. dollars or in such foreign currencies,
currency units or composite currencies as the Company may designate at the time
of offering. The Company will set forth the specific currency, currency unit or
composite currency, interest rate (if any), issue price, and maturity date of
any Note in the related Pricing Supplement to this Prospectus Supplement. Unless
otherwise specified in the applicable Pricing Supplement, Agents will not sell
Notes denominated in other than U.S. dollars or ECUs in, or to residents of, the
country issuing the Specified Currency. See "Description of Notes."
 
    Except as otherwise indicated in the applicable Pricing Supplement, interest
on the Fixed Rate Notes will be payable on each May 15 and November 15 and at
maturity. Interest on Floating Rate Notes will be payable on the dates specified
therein and in the applicable Pricing Supplement. Zero Coupon Notes will not
bear interest.
 
    Unless the Company specifies a Redemption Commencement Date in the
applicable Pricing Supplement, the Notes will not be redeemable prior to their
Stated Maturity.
 
    The Company will issue the Notes offered hereby in permanent global or
definitive certificated form, as specified in the applicable Pricing Supplement.
A permanent global Note representing Book-Entry Notes will be registered in the
name of, or a nominee of, The Depository Trust Company, which will act as
Depositary. Beneficial interests in Book-Entry Notes will be evidenced only by,
and transfers thereof will be effected only through, records maintained by the
Depositary (with respect to participants' interests) and its participants.
Except as described below under "Description of Notes -- Book-Entry Notes,"
owners of beneficial interests in a permanent global Note will not be considered
the Holders thereof and will not be entitled to receive physical delivery of
Notes in definitive form, and no global Note will be exchangeable except for
another global Note of like denomination and terms to be registered in the name
of the Depositary or its nominee. Unless otherwise specified in the applicable
Pricing Supplement, the Notes offered hereby will be issued only in registered
form in denominations of $1,000 and integral multiples thereof, or the
approximate equivalent in the Specified Currency. See "Description of Notes."
                             ---------------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
  AND EXCHANGE COMMISSION OR ANY OTHER STATE SECURITIES COMMISSION PASSED
    UPON THE ACCURACY ORADEQUACY OF THIS PROSPECTUS SUPPLEMENT, ANY PRICING
     SUPPLEMENT HERETO ORTHE PROSPECTUS. ANY REPRESENTATION TO THE
                       CONTRARY IS A CRIMINAL OFFENSE.
                              -------------------
 


                                                                 PRICE TO            AGENTS'                   PROCEEDS TO
                                                                PUBLIC (1)       COMMISSIONS (2)             COMPANY (2)(3)
                                                              --------------  ----------------------  -----------------------------
                                                                                             
Per Note....................................................       100%            .125%-.750%               99.250%-99.875%
Total.......................................................   $250,000,000    $312,500-$1,875,000      $248,125,000-$249,687,500

 
- ----------------
(1) Notes will be issued at 100% of their principal amount, unless otherwise
    specified in the applicable Pricing Supplement.
(2) The Company will pay the Agents a commission ranging from .125% to .750%,
    depending upon the maturity, of the principal amount of any Note sold
    through any such firm as Agent. Commissions and discounts with respect to
    Notes with maturities in excess of 30 years will be negotiated between the
    Company and such Agent at the time of sale. The Company may also sell Notes
    to an Agent as principal for resale to investors and other purchasers at
    varying prices related to prevailing market prices at the time of resale to
    be determined by such Agent or, if so agreed, at a fixed public offering
    price. Unless otherwise specified in the applicable Pricing Supplement, any
    Note sold to an Agent as principal will be purchased by such Agent at a
    price equal to 100% of the principal amount thereof less a percentage equal
    to the commission applicable to an agency sale of a Note of identical
    maturity, and may be resold by such Agent. The Company may also sell Notes
    directly to investors on its own behalf, in which case no commission will be
    payable. The Company has agreed to indemnify the Agents against certain
    liabilities, including liabilities under the Securities Act of 1933.
(3) Before deducting estimated expenses of $287,000 payable by the Company,
    including expenses of the Agents to be reimbursed by the Company.
                             ---------------------
 
    Offers to purchase Notes are being solicited, on a reasonable efforts basis,
from time to time by the Agents on behalf of the Company. Notes may be sold to
the Agents on their behalf at negotiated discounts. The Company reserves the
right to sell Notes directly on its own behalf. The Company also reserves the
right to withdraw, cancel, or modify the offering contemplated hereby without
notice. The Company has not established a termination date for the offering of
the Notes. The Company or the Agents may reject any order as a whole or in part.
See "Supplemental Plan of Distribution."
                             ---------------------
 
GOLDMAN, SACHS & CO.                                        MORGAN STANLEY & CO.
                                                        INCORPORATED
 
           The date of this Prospectus Supplement is August 15, 1996.

    IN CONNECTION WITH THIS OFFERING, THE AGENTS MAY OVER-ALLOT OR EFFECT
TRANSACTIONS WHICH STABILIZE OR MAINTAIN THE MARKET PRICE OF THE NOTES OFFERED
HEREBY AT A LEVEL ABOVE THAT WHICH MIGHT OTHERWISE PREVAIL IN THE OPEN MARKET.
SUCH TRANSACTIONS MAY BE EFFECTED IN THE OVER-THE-COUNTER MARKET OR OTHERWISE.
SUCH STABILIZING, IF COMMENCED, MAY BE DISCONTINUED AT ANY TIME.
 
                                 --------------
 
    THE COMMISSIONER OF INSURANCE OF THE STATE OF NORTH CAROLINA HAS NOT
APPROVED OR DISAPPROVED THIS OFFERING, NOR HAS THE COMMISSIONER PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS.
 
                                 --------------
 
                              DESCRIPTION OF NOTES
 
    THE FOLLOWING DESCRIPTION OF THE PARTICULAR TERMS OF THE NOTES OFFERED
HEREBY (REFERRED TO IN THE PROSPECTUS AS "SENIOR DEBT SECURITIES") SUPPLEMENTS,
AND TO THE EXTENT INCONSISTENT THEREWITH REPLACES, THE DESCRIPTION OF THE
GENERAL TERMS AND PROVISIONS OF SENIOR DEBT SECURITIES SET FORTH IN THE
PROSPECTUS, TO WHICH DESCRIPTION REFERENCE IS HEREBY MADE.
 
GENERAL
 
    The Notes constitute a single series for purposes of the Indenture, dated
September 15, 1990 (the "Indenture"), between the Company and The Chase
Manhattan Bank (National Association), succeeded by merger by The Chase
Manhattan Bank (the "Trustee") as trustee, and are limited in amount as set
forth on the cover page of this Prospectus Supplement. For a description of the
rights attaching to different series of Debt Securities under the Indenture, see
"Description of Debt Securities" in the Prospectus.
 
    The Company will at all times have appointed and maintain a Paying Agent
(which may be the Trustee) authorized to pay the principal of (and premium, if
any) or interest on any Notes on the Company's behalf and having an office or
agency (the "Paying Agent Office") in The City of New York, where the Notes may
be presented or surrendered for payment and notices, designations, or requests
in respect of payments with respect to Notes may be served. The Company has
initially appointed the Trustee as the Paying Agent, with its Paying Agent
Office currently at One Chase Manhattan Plaza, New York, New York.
 
    Unless previously redeemed by the Company or repaid by the Company at the
option of the Holder, a Note will mature on the date ("Stated Maturity") from 9
months or more from its date of issue that is specified on its face and in the
applicable Pricing Supplement. The "maturity" of any Note refers herein to the
date on which its principal becomes due and payable, whether at Stated Maturity,
upon redemption by the Company, repayment by the Company at the option of the
Holder, or otherwise.
 
    Each Note will be denominated in a currency, currency unit or composite
currency ("Specified Currency") as specified on its face and in the applicable
Pricing Supplement. Purchasers of the Notes are required to pay for them by
delivery of the requisite amount of the Specified Currency to an Agent, unless
other arrangements have been made. Unless otherwise specified in the applicable
Pricing Supplement, payments on the Notes will be made in the applicable
Specified Currency in the country issuing the Specified Currency (or, for ECUs,
Brussels), provided that, at the election of the Holder and in certain
circumstances at the Company's option, payments on Notes denominated in other
than U.S. dollars may be made in U.S. dollars. See "Payment of Principal and
Interest."
 
    Each Note will be represented by either a permanent global Note registered
in the name of, or a nominee of, the Depositary (each such Note represented by a
permanent global Note being referred to below as a "Book-Entry Note") or a
certificate issued in definitive registered form, without coupons, as set forth
in the applicable Pricing Supplement. Except as set forth under "Book-Entry
Notes" below, Book-Entry Notes will not be issuable in certificated form. So
long as the Depositary or its nominee is the registered holder of any permanent
global Note, the Depositary or its nominee, as the case may be, will
 
                                      S-2

be considered the sole Holder of the Book-Entry Note or Notes represented by
such permanent global Note for all purposes under the Indenture and the Notes.
For a further description of the respective forms, denominations, and transfer
and exchange procedures for any such permanent global Note and the Book-Entry
Notes, refer to "Book-Entry Notes" below and to the applicable Pricing
Supplement. Unless otherwise specified in the applicable Pricing Supplement, the
authorized denominations of any Note denominated in U.S. dollars will be $1,000
and integral multiples thereof. The authorized denominations of any Note
denominated in other than U.S. dollars will be the amount of the Specified
Currency for such Note equivalent, at the noon buying rate in The City of New
York for cable transfers for such Specified Currency (the "Exchange Rate") on
the sixth Business Day in The City of New York and in the country issuing such
currency (or, for ECUs, Brussels) next preceding the date of issue of such Note,
to U.S. $1,000 (rounded to the nearest 1,000 units of such Specified Currency)
and any greater amount that is an integral multiple of 1,000 units of such
Specified Currency unless specified in the applicable Pricing Supplement.
 
    Notes will be sold in individual issues of Notes having such interest rate
or interest rate formula, if any, Stated Maturity, and date of original issuance
as shall be selected by the initial purchasers and agreed to by the Company.
Interest rates offered by the Company with respect to the Notes may differ
depending upon, among other things, the aggregate principal amount of the Notes
purchased in any single transaction. Unless otherwise indicated in the
applicable Pricing Supplement, each Note, except any Zero Coupon Note (as
hereinafter defined), will bear interest at a fixed rate or a rate determined by
reference to one or more of the Commercial Paper Rate, the Prime Rate, LIBOR,
the Treasury Rate, the CD Rate, CMT Rate or the Federal Funds Rate, as adjusted
by the Spread and/or Spread Multiplier, if any, applicable to such Note. See
"Interest Rate." The Notes may be issued as Zero Coupon Notes ("Zero Coupon
Notes"). Zero Coupon Notes will be issued at a discount from the principal
amount payable at maturity thereof, but holders of Zero Coupon Notes will not
receive periodic payments of interest thereon.
 
    The Notes (including any Zero Coupon Note) may be issued with original issue
discount as defined for United States federal income tax purposes. Holders of
Notes issued with original issue discount may be required to include amounts in
gross income for federal income tax purposes in advance of the receipt of the
cash to which such income is attributable. See "United States Taxation" in this
Prospectus Supplement.
 
    The Notes will not be subject to any sinking fund and, unless the Company
specifies an initial date on which a Note may be redeemed by the Company ( a
"Redemption Commencement Date") in the applicable Pricing Supplement, will not
be redeemable before their maturity. If the Company does specify a Redemption
Commencement Date for any Note, the applicable Pricing Supplement will also
specify one or more redemption prices ("Redemption Prices") and the redemption
period or periods ("Redemption Periods") during which such Redemption Prices
shall apply. Unless otherwise specified in the Pricing Supplement, any such Note
shall be redeemable at the Company's option at any time on or after such
specified Redemption Commencement Date at the specified Redemption Price
applicable to the Redemption Period during which such Note is to be redeemed,
together with interest accrued to the date fixed for redemption (the "Redemption
Date").
 
    The Notes (other than Book-Entry Notes) may be presented for registration of
transfer or exchange at the Paying Agent Office in The City of New York. With
respect to transfers of Book-Entry Notes and exchanges of permanent global Notes
representing Book-Entry Notes, see "Description of Notes -- Book-Entry Notes."
 
    The Indenture provisions relating to satisfaction and discharge and legal
and covenant defeasance which are described in the accompanying Prospectus under
"Description of Debt Securities -- Satisfaction and Discharge of Indentures"
will apply to the Notes.
 
                                      S-3

INTEREST RATE
 
    Each Note, other than a Zero Coupon Note, will bear interest from its date
of issue or from the most recent Interest Payment Date to which interest on such
Note has been paid or duly provided for at the fixed rate per annum, or at the
rate per annum determined pursuant to the interest rate formula, stated therein
and in the applicable Pricing Supplement until the principal thereof is paid or
made available for payment. Interest will be payable on each Interest Payment
Date and at maturity or earlier date of redemption by the Company or repayment
by the Company at the option of the Holder, as specified below under "Payment of
Principal and Interest."
 
    Each Note, other than a Zero Coupon Note, will bear interest at either:
 
       (a) a fixed rate ( a "Fixed Rate Note"); or
 
       (b) a variable rate determined by reference to an interest rate formula
           (a "Floating Rate Note"), which may be adjusted by adding or
    subtracting the Spread and/or multiplying by the Spread Multiplier (each
    term defined below).
 
    A Floating Rate Note may also have either or both:
 
       (a) a maximum, or ceiling, on the rate of interest that may accrue during
           any interest period (a "Maximum Rate"); and
 
       (b) a minimum, or floor, on the rate of interest that may accrue during
           any interest period (a "Minimum Rate").
 
    The "Spread" is the number of basis points specified in the applicable
Pricing Supplement as applying to the Interest Rate Basis (as defined below) for
such Note, and the "Spread Multiplier" is the percentage specified in the
applicable Pricing Supplement as applying to the Interest Rate Basis for such
Note.
 
    "Market Day" means:
 
       (a) with respect to any Note, any Business Day in The City of New York;
           and
 
       (b) with respect to any LIBOR Note, any Business Day in The City of New
           York which is also a day on which dealings in deposits in U.S.
    dollars are transacted in the London interbank market (a "London Business
    Day"). "Business Day," as used herein for any particular location, means
    each Monday, Tuesday, Wednesday, Thursday and Friday that is not a day on
    which banking institutions in such location are authorized or obligated by
    law or executive order to close.
 
    "Index Maturity" means, for a Floating Rate Note, the period to maturity of
the interest or obligation on which the interest rate formula is based, as
specified in the applicable Pricing Supplement. Unless otherwise provided in the
applicable Pricing Supplement, the Trustee will be the calculation agent (the
"Calculation Agent") for Floating Rate Notes.
 
    The applicable Pricing Supplement relating to a Fixed Rate Note will
designate a fixed rate of interest per annum payable on such Fixed Rate Note,
the Interest Payment Dates (if other than May 15 and November 15), the Regular
Record Dates (if other than May 1 and November 1), and, if applicable, the
Redemption Commencement Date, Redemption Prices and Redemption Periods relating
to such Fixed Rate Note. The applicable Pricing Supplement relating to a
Floating Rate Note will designate an interest rate basis (the "Interest Rate
Basis") for such Floating Rate Note. The Interest Rate Basis for each Floating
Rate Note will be one or more of the following:
 
       (a) the Commercial Paper Rate for "Commercial Paper Rate Notes";
 
       (b) the Prime Rate for "Prime Rate Notes";
 
       (c) LIBOR for "LIBOR Notes";
 
       (d) the Treasury Rate for "Treasury Rate Notes";
 
                                      S-4

       (e) the CD Rate for "CD Rate Notes";
 
       (f) the CMT Rate for "CMT Rate Notes";
 
       (g) the Federal Funds Rate for "Federal Funds Rate Notes"; or
 
       (h) such other interest rate formula as such Pricing Supplement sets
           forth.
 
    The applicable Pricing Supplement for a Floating Rate Note will specify the
Interest Rate Basis and, if applicable, the Calculation Agent, the Index
Maturity, the Spread and/or Spread Multiplier, the Maximum Rate, the Minimum
Rate, the Initial Interest Rate, the Interest Payment Dates, the Regular Record
Dates, the Calculation Date, the Interest Determination Date, and the Interest
Reset Date for such Note.
 
    The interest rate on each Floating Rate Note will be reset daily, weekly,
monthly, quarterly, semi-annually, annually, or otherwise (such period being the
"Interest Reset Period" for such Floating Rate Note, and the first date of each
Interest Reset Period being an "Interest Reset Date"), as specified in the
applicable Pricing Supplement. The Interest Reset Date will be:
 
       (a) for Floating Rate Notes (other than Treasury Rate Notes) that reset
           daily, each Business Day;
 
       (b) for Floating Rate Notes (other than Treasury Rate Notes) that reset
           weekly, the Wednesday of each week;
 
       (c) for Treasury Rate Notes that reset weekly, the Tuesday of each week,
           except as provided below;
 
       (d) for Floating Rate Notes that reset monthly, the third Wednesday of
           each month;
 
       (e) for Floating Rate Notes that reset quarterly, the third Wednesday of
           March, June, September and December;
 
       (f) for Floating Rate Notes that reset semi-annually, the third Wednesday
           of two months of each year as specified in the applicable Pricing
    Supplement;
 
       (g) for Floating Rate Notes that reset annually, the third Wednesday of
           one month of each year as specified in the applicable Pricing
    Supplement; and
 
       (h) for Floating Rate Notes that reset at intervals other than those
           described above, the days specified in the applicable Pricing
    Supplement;
 
PROVIDED, HOWEVER, that the interest rate in effect from the date of issue to
the first Interest Reset Date for a Floating Rate Note will be the initial
Interest Rate (as set forth in the applicable Pricing Supplement).
 
    If any Interest Reset Date for any Floating Rate Note would otherwise be a
day that is not a Market Day for such Floating Rate Note, the Interest Reset
Date for such Floating Rate Note shall be postponed to the next day that is a
Market Day for such Floating Rate Note (except that for a LIBOR Note, if such
Market Day is in the next succeeding calendar month, such Interest Reset Date
shall be the immediately preceding Market Day).
 
    The Interest Determination Date pertaining to an Interest Reset Date for a
Commercial Paper Rate Note (the "Commercial Paper Interest Determination Date"),
for a Prime Rate Note (the "Prime Rate Interest Determination Date"), for a CD
Rate Note (the "CD Rate Interest Determination Date"), for a CMT Rate Note (the
"CMT Rate Interest Determination Date") and for a Federal Funds Rate Note (the
"Federal Funds Rate Interest Determination Date") will be the second Market Day
preceding such Interest Reset Date. The Interest Determination Date pertaining
to an Interest Reset Date for a LIBOR Note (the "LIBOR Interest Determination
Date") will be the second London Business Day preceding such Interest Reset
Date. The Interest Determination Date pertaining to an Interest Reset Date for a
Treasury Rate Note (the "Treasury Interest Determination Date") will be the day
of the week in which such Interest Reset Date falls on which Treasury bills
would normally be auctioned. Treasury bills are usually sold at auction on the
Monday of each week, unless that day is a legal holiday, in which case the
auction is usually held on
 
                                      S-5

the following Tuesday, except that such auction may be held on the preceding
Friday. If, as the result of a legal holiday, an auction is so held on the
preceding Friday, such Friday will be the Treasury Interest Determination Date
pertaining to the Interest Reset Date occurring in the next succeeding week. If
an auction date shall fall on any Interest Reset Date for a Treasury Rate Note,
then such Interest Reset Date shall instead be the first Market Day immediately
following such auction date.
 
    All percentages resulting from any calculations referred to in this
Prospectus Supplement will be rounded, if necessary, to the nearest one
hundred-thousandth of a percentage point with five one-millionths of a
percentage point rounded upward (e.g., 9.876546% (or .09876546) being rounded to
9.87655% (or .0987655)), and all U.S. dollar amounts used in or resulting from
such calculations will be rounded to the nearest cent (with one-half cent being
rounded upwards).
 
    In addition to any maximum interest rate that may apply to a Floating Rate
Note under the above provisions, the interest rate on the Floating Rate Notes
will in no event be higher than the maximum rate permitted by New York law, as
the same may be modified by United States law of general application. Under
present New York law, the maximum rate of interest is 25% per annum on a simple
interest basis, with certain exceptions. The limit may not apply to Floating
Rate Notes in which U.S. $2,500,000 or more has been invested.
 
    Upon the request of the Holder of any Floating Rate Note, the Calculation
Agent will provide the interest rate then in effect, and, if determined, the
interest rate that will become effective on the next Interest Reset Date for
such Floating Rate Note. Unless otherwise specified in the applicable Pricing
Supplement, the "Calculation Date," if applicable, pertaining to any Interest
Determination Date will be the earlier of (i) the tenth calendar day after such
Interest Determination Date, or, if such day is not a Business Day, the next
succeeding Business Day or (ii) the Business Day immediately preceding the
applicable Interest Payment Date or the Stated Maturity, as the case may be. The
Calculation Agent's determination of any interest rate will be final and binding
in the absence of manifest error.
 
COMMERCIAL PAPER RATE NOTES
 
    Commercial Paper Rate Notes will bear interest at the interest rates
(calculated with reference to the Commercial Paper Rate and the Spread and/or
Spread Multiplier, if any), and be payable on the dates, specified on the face
of the Commercial Paper Rate Note and in the applicable Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, "Commercial
Paper Rate" means, for any Interest Reset Date, the Money Market Yield
(calculated as described below) of the per annum rate (quoted on a bank discount
basis) for the relevant Commercial Paper Interest Determination Date for
commercial paper having the specified Index Maturity as published by the Board
of Governors of the Federal Reserve System in "Statistical Release H.15(519),
Selected Interest Rates" or any successor publication of the Board of Governors
of the Federal Reserve System ("H.15(519)") under the heading "Commercial
Paper." If such rate is not published before 3:00 p.m., New York City time, on
the relevant Calculation Date, then the Commercial Paper Rate for such Interest
Reset Date shall be the Money Market Yield of such rate on such Commercial Paper
Interest Determination Date for commercial paper having the specified Index
Maturity as published by the Federal Reserve Bank of New York in its daily
statistical release, "Composite 3:30 p.m. Quotations for U.S. Government
Securities" or any successor publication published by the Federal Reserve Bank
of New York ("Composite Quotations") under the heading "Commercial Paper." If by
3:00 p.m., New York City time, on such Calculation Date such rate is not yet
published in either H.15(519) or Composite Quotations, the Commercial Paper Rate
for such Interest Reset Date shall be calculated by the Calculation Agent and
shall be the Money Market Yield of the arithmetic mean of the offered per annum
rates (quoted on a bank discount basis), as of 11:00 a.m., New York City time,
on such Commercial Paper Interest Determination Date, of three leading dealers
of commercial paper in The City of New York (which may include the Agents)
selected by the Calculation Agent for commercial paper of the specified Index
Maturity placed for an industrial issuer whose bond rating is "AA," or the
equivalent, from a nationally recognized rating agency; PROVIDED, HOWEVER, that
if
 
                                      S-6

fewer than three dealers selected by the Calculation Agent are quoting as
mentioned in this sentence, the Commercial Paper Rate for such Interest Reset
Date will be the Commercial Paper Rate in effect on such Commercial Paper
Interest Determination Date.
 
    "Money Market Yield" shall be a yield (expressed as a percentage) calculated
in accordance with the following formula:
 
                             
                                    360 X D
   MONEY MARKET YIELD = 100  X   -------------
                                 360 - (D X M)


 
where "D" refers to the per annum rate for commercial paper quoted on a bank
discount basis and expressed as a decimal and "M" refers to the actual number of
days in the period from the Interest Reset Date to but excluding the day that
numerically corresponds to such Interest Rate Date (or, if there is not any such
numerically corresponding day, the last day) in the calendar month that is the
number of months corresponding to the specified Index Maturity after the month
in which such Interest Reset Date falls.
 
PRIME RATE NOTES
 
    Prime Rate Notes will bear interest at the interest rates (calculated with
reference to the Prime Rate and the Spread and/or Spread Multiplier, if any),
and will be payable on the dates specified on their faces and in the applicable
Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, "Prime
Rate" means, for any Interest Reset Date, the rate set forth for the relevant
Prime Rate Interest Determination Date in H.15(519) under the heading "Bank
Prime Loan." If such rate is not published before 9:00 a.m., New York City time,
on the relevant Calculation Date, then the Prime Rate for such Interest Reset
Date will be the arithmetic mean of the rates of interest publicly announced by
each bank that appears on the display designated as page "USPRIME1" on the
Reuters Monitor Money Rates Service (or such other page as may replace the
USPRIME1 page on that service for the purpose of displaying prime rates or base
lending rates of major United States banks) ("Reuters Screen USPRIME1 Page") as
such bank's prime rate or base lending rate as in effect for such Prime Rate
Interest Determination Date as quoted on the Reuters Screen USPRIME1 Page on
such Prime Rate Interest Determination Date. If fewer than four such rates
appear on the Reuters Screen USPRIME1 Page on such Prime Rate Interest
Determination Date, the Prime Rate for such Interest Reset Date will be the
arithmetic mean of the prime rates or base lending rates (quoted on the basis of
the actual number of days in the year divided by a 360-day year) as of the close
of business on such Prime Rate Interest Determination Date by three major banks
in The City of New York selected by the Calculation Agent; PROVIDED, HOWEVER,
that if fewer than three banks selected as provided above by the Calculation
Agent are quoting as mentioned in this sentence, the Prime Rate for such
Interest Reset Date will be the Prime Rate in effect on such Prime Rate Interest
Determination Date.
 
LIBOR NOTES
 
    LIBOR Notes will bear interest at the interest rates (calculated with
reference to LIBOR and the Spread and/or Spread Multiplier, if any), and will be
payable on the dates, specified on the face of the LIBOR Note and in the
applicable Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, LIBOR for
any Interest Reset Date will be determined by the Calculation Agent as follows:
 
       (a) The Calculation Agent will determine either (i) the arithmetic mean
           of the offered rates for deposits in U.S. dollars for the period of
    the applicable Index Maturity which appear on the Reuters Screen LIBO Page
    at approximately 11:00 a.m., London time, on such LIBOR Interest
    Determination Date if at least two such offered rates appear on the Reuters
    Screen LIBO Page ("LIBOR Reuters"), or (ii) the rate for deposits in U.S.
    dollars for the period of the applicable Index Maturity that appears on the
    Telerate Page 3750 as of 11:00 a.m., London time, on such LIBOR Interest
    Determination Date ("LIBOR Telerate"). "Reuters Screen LIBO Page" means the
    display designated as Page "LIBO" on the Reuters Monitor Money Rate Service
    (or such other page as may replace the
 
                                      S-7

    LIBO page on the service for the purpose of displaying London interbank
    offered rates of major banks). "Telerate Page 3750" means the display
    designated as page "3750" on the Telerate Service (or such other page as may
    replace the 3750 page on that service or such other service or services as
    may be nominated by the British Bankers' Association for the purpose of
    displaying London interbank offered rates for U.S. dollar deposits). If
    neither LIBOR Reuters nor LIBOR Telerate is specified in the applicable
    Pricing Supplement, LIBOR will be determined as if LIBOR Telerate had been
    specified. If fewer than two offered rates appear on the Reuters Screen LIBO
    Page, or if no rate appears on the Telerate Page 3750, as applicable, LIBOR
    in respect of that LIBOR Interest Determination Date will be determined as
    if the parties had specified the rate described in (b) below.
 
       (b) If fewer than two offered rates appear on the Reuters Screen LIBO
           Page or no rate appears on Telerate Page 3750, as applicable, the
    Calculation Agent will request the principal London offices of four major
    banks in the London interbank market, as selected by the Calculation Agent,
    to provide the Calculation Agent with its offered quotations for deposits in
    U.S. dollars for the period of the applicable Index Maturity to prime banks
    in the London interbank market at approximately 11:00 a.m., London time,
    commencing on the second London Business day immediately following such
    LIBOR Interest Determination Date and in a principal amount equal to an
    amount of not less than U.S.$1 million that is representative of a single
    transaction in such market at such time. If at least two quotations are
    provided, LIBOR in respect of that LIBOR Interest Determination Date will be
    the arithmetic mean of rates quoted by three major banks in The City of New
    York selected by the Calculation Agent at approximately 11:00 a.m., New York
    City time, commencing on the second London Business Day immediately
    following such LIBOR Interest Determination Date for loans in U.S. dollars
    to leading European banks, for the period of the applicable Index Maturity
    and in a principal amount equal to an amount of not less than U.S. $1
    million that is representative for a single transaction in such market at
    such time; PROVIDED, HOWEVER, that if fewer than three banks selected as
    aforesaid by the Calculation Agent are quoting rates as mentioned in this
    sentence, the rate of interest in effect for the applicable period will be
    the LIBOR in effect on such LIBOR Interest Determination Date.
 
TREASURY RATE NOTES
 
    Treasury Rate Notes will bear interest at the interest rates (calculated
with reference to the Treasury Rate and the Spread and/or Spread Multiplier, if
any) and will be payable on the dates specified on the face of the Treasury Rate
Note and in the applicable Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, "Treasury
Rate" means, for any Interest Reset Date, the rate for the auction on the
relevant Treasury Interest Determination Date of direct obligations of the
United States ("Treasury Bills") having the specified Index Maturity as
published in H.15(519) under the heading "U.S. Government Securities/Treasury
Bills/Auction Average (Investment)" or, if not so published by 9:00 a.m., New
York City time, on the relevant Calculation Date, the auction average rate
(expressed as a bond equivalent, on the basis of a year of 365 or 366 days, as
applicable, and applied on a daily basis) for such auction as otherwise
announced by the United States Department of the Treasury. If the results of
such auction of Treasury bills having the specified Index Maturity are not
published or reported as provided above by 3:00 p.m., New York City time, on
such Calculation Date, or if no such action is held during such week, then the
Treasury Rate shall be the rate set forth in H.15(519) for the relevant Treasury
Interest Determination Date for the specified Index Maturity under the heading
"U.S. Government Securities/Treasury Bills/Secondary Market." If such rate is
not so published by 3:00 p.m., New York City time, on the relevant Calculation
Date, the Treasury Rate for such Interest Reset Date shall be calculated by the
Calculation Agent and shall be a yield to maturity (expressed as a bond
equivalent, on the basis of a year of 365 or 366 days, as applicable, and
applied on a daily basis) of the arithmetic mean of the secondary market bid
rates as of approximately 3:30 p.m., New York City time, on such Treasury
Interest Determination Date, of three primary United States government
securities dealers in The City of New York selected by the Calculation Agent for
the issue of Treasury bills with a remaining maturity closest to the specified
Index Maturity; PROVIDED, HOWEVER, that if fewer than three dealers
 
                                      S-8

selected as provided above by the Calculation Agent are quoting as mentioned in
this sentence, the Treasury Rate for such Interest Reset Date will be the
Treasury Rate in effect on such Treasury Interest Determination Date.
 
CD RATE NOTES
 
    CD Rate Notes will bear interest at the interest rates (calculated with
reference to the CD Rate and the Spread and/or Spread Multiplier, if any), and
will be payable on the dates, specified on the face of the CD Rate Note and in
the applicable Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, "CD Rate"
means, for any Interest Reset Date, the rate for the relevant CD Interest
Determination Date for negotiable certificates of deposit having the specified
Index Maturity as published in H.15(519) under the heading "CDs (Secondary
Market)." If such rate is not published before 9:00 a.m., New York City time, on
the relevant Calculation Date, then the CD Rate for such Interest Reset Date
shall be the rate on such CD Rate Interest Determination Date for negotiable
certificates of deposit having the specified Index Maturity as published in
Composite Quotations under the heading "Certificates of Deposit." If by 3:00
p.m., New York City time, on such Calculation Date such rate is not published in
either H.15(519) or Composite Quotations, the CD Rate for such Interest Reset
Date shall be calculated by the Calculation Agent and shall be the arithmetic
mean of the secondary market offered rates, as of 10:00 a.m., New York City
time, on such CD Rate Interest Determination Date, of three leading nonbank
dealers of negotiable U.S. dollar certificates of deposit in The City of New
York selected by the Calculation Agent for negotiable certificates of deposit of
major United States money market banks with a remaining maturity closest to the
specified Index Maturity in a denomination of U.S. $5,000,000; PROVIDED,
HOWEVER, that if fewer than three dealers selected as provided above by the
Calculation Agent are quoting as mentioned in this sentence, the CD Rate for
such Interest Reset Date will be the CD Rate in effect on such CD Rate Interest
Determination Date.
 
CMT RATE NOTES
 
    CMT Rate Notes will bear interest at the interest rates (calculated with
reference to the CMT Rate and the Spread and/or Spread Multiplier, if any), and
will be payable on the dates, specified on the face of the CMT Rate Note and in
the applicable Pricing Supplement.
 
    Unless otherwise specified in the applicable Pricing Supplement, "CMT Rate"
means, with respect to any Interest Determination Date relating to an Interest
Reset Date For a Floating Rate Note for which the interest rate is determined
with reference to the CMT Rate (a "CMT Rate Interest Determination Date"), the
rate displayed on the Designated CMT Telerate Page under the caption
"...Treasury Constant Maturities...Federal Reserve Board Release H.15...Mondays
Approximately 3:45 P.M.," under the column for the Designated CMT Maturity Index
for (i) if the Designated CMT Telerate Page is 7055, the rate on such CMT Rate
Interest Determination Date and (ii) if the Designated CMT Telerate Page is
7052, the week, or the month, as applicable, ended immediately preceding the
week in which the related CMT Rate Interest Determination Date occurs. If such
rate is no longer displayed on the relevant page or is not displayed by 3:00
P.M., New York City time, on the related Calculation Date, then the CMT Rate for
such CMT Rate Interest Determination Date will be such treasury constant
maturity rate for the Designated CMT Maturity Index as published in the relevant
H.15(519). If such rate is no longer published or is not published by 3:00 P.M.,
New York City time, on the related Calculation Date, then the CMT Rate on such
CMT Rate Interest Determination Date will be such treasury constant maturity
rate for the Designated CMT Maturity Index (or other United States Treasury rate
for the Designated CMT Maturity Index) for the CMT Rate Interest Determination
Date with respect to such Interest Reset Date as may then be published by either
the Board of Governors of the Federal Reserve System or the United States
Department of the Treasury that the Calculation Agent determines to be
comparable to the rate formerly displayed on the Designated CMT Telerate Page
and published in the relevant H.15(519). If such information is not provided by
3:00 P.M., New York City time, on the related Calculation Date, then the CMT
Rate on the CMT Rate Interest Determination Date will be calculated by the
Calculation Agent and will be a yield to
 
                                      S-9

maturity, based on the arithmetic mean of the secondary market closing offer
side prices as of approximately 3:30 P.M., New York City time, on such CMT Rate
Interest Determination Date reported, according to their written records, by
three leading primary United States government securities dealers (each, a
"Reference Dealer") in The City of New York (which may include the Agent or its
affiliates) selected by the Calculation Agent (from five such Reference Dealers
selected by the Calculation Agent and eliminating the highest quotation (or, in
the event of equality, one of the highest) and the lowest quotation (or, in the
event of equality, one of the lowest)), for the most recently issued direct
noncallable fixed rate obligations of the United States ("Treasury Notes") with
an original maturity of approximately the Designated CMT Maturity Index and a
remaining term to maturity of not less than such Designated CMT Maturity Index
minus one year. If the Calculation Agent is unable to obtain three such Treasury
Note quotations, the CMT Rate on such CMT Rate Interest Determination Date will
be calculated by the Calculation Agent and will be a yield to maturity based on
the arithmetic mean of the secondary market offer side prices as of
approximately 3:30 P.M., New York City time, on such CMT Rate Interest
Determination Date of three Reference Dealers in The City of New York (from five
such Reference Dealers selected by the Calculation Agent and eliminating the
highest quotation (or, in the event of equality, one of the highest) and the
lowest quotation (or, in the event of equality, one of the lowest)), for
Treasury Notes with an original maturity of the number of years that is the next
highest to the Designated CMT Maturity Index and a remaining term to maturity
closest to the Designated CMT Maturity Index and in an amount of at least $100
million. If three or four (and not five) of such Reference Dealers are quoting
as described above, then the CMT Rate will be based on the arithmetic mean of
the offer prices obtained and neither the highest nor the lowest of such quotes
will be eliminated; PROVIDED, HOWEVER, that if fewer than three Reference
Dealers so selected by the Calculation Agent are quoting as mentioned herein,
the CMT Rate determined as of such CMT Rate Interest Determination Date will be
the CMT Rate in effect on such CMT Rate Interest Determination Date. If two
Treasury Notes with an original maturity as described in the second preceding
sentence have remaining terms to maturity equally close to the Designated CMT
Maturity Index, the Calculation Agent will obtain from five Reference Dealers
quotations for the Treasury Note with the shorter remaining term to maturity.
 
    "Designated CMT Telerate Page" means the display on the Dow Jones Telerate
Service on the page specified in the applicable Pricing Supplement (or any other
page as may replace such page on that service for the purpose of displaying
Treasury Constant Maturities as reported in H.15(519)) for the purpose of
displaying Treasury Constant Maturities as reported in H.15(519). If no such
page is specified in the applicable Pricing Supplement, the Designated CMT
Telerate Page shall be 7052 for the most recent week.
 
    "Designated CMT Maturity Index" means the original period to maturity of the
U.S. Treasury securities (either 1, 2, 3, 5, 7, 10, 20 or 30 years) specified in
the applicable Pricing Supplement with respect to which the CMT Rate will be
calculated. If no such maturity is specified in the applicable Pricing
Supplement, the Designated CMT Maturity Index shall be 2 years.
 
FEDERAL FUNDS RATE NOTES
 
    Federal Funds Rates Notes will bear interest at the interest rates
(calculated with reference to the Federal Funds Rate and the Spread and/or
Spread Multiplier, if any), and will be payable on the dates, specified on the
face of the Federal Funds Rate Note and in the applicable Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement, "Federal
Funds Rate" means, for any Interest Reset Date, the rate on the relevant Federal
Funds Interest Determination Date for Federal Funds as published in H.15(519)
under the heading "Federal Funds (Effective)." If such rate is not published
before 9:00 a.m., New York City time, on the relevant Calculation Date, then the
Federal Funds Rate for such Interest Reset Date will be the rate on such Federal
Funds Interest Determination Date as published in Composite Quotations under the
heading "Federal Funds/Effective Rate." If by 3:00 p.m., New York City time, on
such Calculation Date such rate is not published in either H.15(519) or
Composite Quotations, the Federal Funds Rate for such Interest Reset Date shall
be calculated by the Calculation Agent and shall be the arithmetic mean of the
rates, as of 9:00 a.m., New York City time, on such Federal
 
                                      S-10

Funds Interest Determination Date, for the last transaction in overnight Federal
Funds arranged by three leading brokers of Federal Funds transactions in The
City of New York selected by the Calculation Agent; PROVIDED, HOWEVER, that if
fewer than three brokers selected by the Calculation Agent are quoting as
mentioned in this sentence, the Federal Funds Rate for such Interest Reset Date
will be the Federal Funds Rate in effect on such Federal Funds Interest
Determination Date.
 
PAYMENT OF PRINCIPAL AND INTEREST
 
    Unless otherwise specified in the applicable Pricing Supplement, payments of
principal of (and premium, if any) and interest on all Notes will be made in the
applicable Specified Currency; PROVIDED, HOWEVER, that payments of principal
(and premium, if any) and interest on Notes denominated in other than U.S.
dollars will nevertheless be made in U.S. dollars:
 
       (a) at the option of the Holders of such Notes under the procedures
           described in the two following paragraphs; and
 
       (b) at the Company's option in the case of imposition of exchange
           controls or other circumstances beyond the Company's control as
    described in the last paragraph under this heading.
 
    Unless otherwise specified in the applicable Pricing Supplement, and except
as provided in the next paragraph, payments of interest and principal (and
premium, if any) for any Note denominated in other than U.S. dollars will be
made in U.S. dollars if the registered Holder of such Note on the relevant
Regular Record Date, or at maturity, as the case may be, has transmitted a
written request for such payment in U.S. dollars to the Paying Agent at the
Paying Agent Office in The City of New York on or before such Regular Record
Date, or the date 15 days before maturity, as the case may be. Such request may
be in writing (mailed or hand delivered) or by cable, telex, or other form of
facsimile transmission. Any such request made for any Note by a registered
Holder will remain in effect for any further payments of interest and principal
(and premium, if any) on such Note payable to such Holder, unless such request
is revoked on or before the relevant Regular Record Date or the date 15 days
before maturity, as the case may be. Holders of Notes denominated in other than
U.S. dollars whose Notes are registered in the name of a broker or nominee
should contact such broker or nominee to determine whether and how to elect to
receive payments in U.S. dollars.
 
    The U.S. dollar amount to be received by a Holder of a Note denominated in
other than U.S. dollars who elects to receive payment in U.S. dollars will be
based on the highest bid quotation in The City of New York received by the
Exchange Rate Agent (as defined below) as of 11:00 a.m., New York City time on
the second Business Day next preceding the applicable payment date from three
recognized foreign exchange dealers (one of which may be the Exchange Rate
Agent) for the purchase by the quoting dealer of the Specified Currency for U.S.
dollars for settlement on such payment date in the aggregate amount of the
Specified Currency payable to all Holders of Notes electing to receive U.S.
dollar payments and at which the applicable dealer commits to execute a
contract. If three such bid quotations are not available on the second Business
Day preceding the date of payment of principal (and premium, if any) or interest
for any Note, such payment will be made in the Specified Currency. All currency
exchange costs associated with any payment in U.S. dollars on any such Note will
be borne by the Holder thereof by deductions from such payment. The Exchange
Rate Agent (the "Exchange Rate Agent") with respect to any Notes denominated in
other than U.S dollars will be specified in the applicable Pricing Supplement.
 
    Interest will be payable to the person in whose name a Note is registered
(which for a permanent global Note representing Book-Entry Notes will be the
Depositary or a nominee of the Depositary) at the close of business on the
Regular Record Date next preceding each Interest Payment Date; PROVIDED,
HOWEVER, that interest payable at maturity will be payable to the person to whom
principal shall be payable (which for permanent global Notes representing
Book-Entry Notes, will be the Depositary or a nominee of the Depositary). The
first payment of interest on any Note originally issued between a Regular Record
Date and an Interest Payment Date will be made on the second such Interest
Payment Date next succeeding its date of issue to the registered owner on the
Regular Record Date relating to
 
                                      S-11

such second Interest Payment Date. Unless otherwise indicated in the applicable
Pricing Supplement, the "Regular Record Date" for any Floating Rate Note shall
be the date 15 calendar days before each Interest Payment Date, whether or not
such date shall be a Business Day, and the "Regular Record Date" for any Fixed
Rate Note shall be the May 1 and November 1 next preceding the May 15 and
November 15 Interest Payment Dates unless otherwise indicated in the applicable
Pricing Supplement.
 
    Unless otherwise indicated in the applicable Pricing Supplement and except
as provided below, interest will be payable:
 
       (a) for Floating Rate Notes that reset daily, on the third Wednesday of
           each month or on the third Wednesday of March, June, September, and
    December of each year (as indicated in the applicable Pricing Supplement);
 
       (b) for Floating Rate Notes that reset weekly, on the third Wednesday of
           each month or on the third Wednesday of March, June, September, and
    December of each year (as indicated in the applicable Pricing Supplement);
 
       (c) for Floating Rate Notes that reset monthly, on the third Wednesday of
           each month or on the third Wednesday of March, June, September, and
    December of each year (as indicated in the applicable Pricing Supplement);
 
       (d) for Floating Rate Notes that reset quarterly, on the third Wednesday
           of March, June, September, and December of each year;
 
       (e) for Floating Rate Notes that reset semi-annually, on the third
           Wednesday of the two months of each year specified in the applicable
    Pricing Supplement;
 
       (f) for Floating Rate Notes that reset annually, on the third Wednesday
           of the month specified in the applicable Pricing Supplement; and
 
       (g) for Floating Rate Notes that reset at intervals other than those
           described above, on the days specified in the applicable Pricing
    Supplement,
 
each an "Interest Payment Date," and in each case, at maturity. If an Interest
Payment Date (other than at Stated Maturity, a Redemption Date or an Optional
Repayment Date (as defined below under "Repayment at the Option of the Holder"))
with respect to any Floating Rate Note would otherwise fall on a day that is not
a Market Day with respect to such Note (and for any Note denominated in other
than U.S. dollars, a Business Day in the country issuing the Specified Currency
(or, for ECUs, Brussels)), such Interest Payment Date will be on the next
succeeding Market Day (with interest accruing to but excluding the next
succeeding Market Day) (or, in the case of a LIBOR Note, if such day falls in
the next calendar month, the next preceding Market Day (with interest accruing
to but excluding the next preceding Market Day)). If the Stated Maturity,
Redemption Date or Optional Repayment Date of a Floating Rate Note falls on a
day that is not a Market Day (and for any Note denominated in other than U.S.
dollars, a Business Day in the country issuing the Specified Currency (or, for
ECUs, Brussels)), the required payment of principal, premium, if any, and
interest will be made on the next succeeding Market Day as if made on the date
such payment was due, and no interest will accrue on such payment for the period
from and after the Stated Maturity, Redemption Date or Optional Repayment Date,
as the case may be, to the date of such payment on the next succeeding Market
Day.
 
    Unless otherwise specified in the applicable Pricing Supplement, interest
payments in respect of Fixed Rates Note and Floating Rate Notes will equal the
amount of interest accrued from and including the immediately preceding Interest
Payment Date in respect of which interest has been paid or duly made available
for payment (or from and including the date of issue, if no interest has been
paid or duly made available for payment) to but excluding the applicable
Interest Payment Date or the Stated Maturity, as the case may be.
 
    For a Floating Rate Note, accrued interest from (and including) the date of
issue or from (and including) the last date to which interest has been paid is
calculated by multiplying the face amount of
 
                                      S-12

such Floating Rate Note by an accrued interest factor. Such accrued interest
factor is computed by adding the interest factor calculated for each day from
(and including) the date of issue, or from (and including) the last date to
which interest has been paid, but excluding the date for which accrued interest
is being calculated. The interest factor (expressed as a decimal) for each such
day is computed by dividing the interest rate (expressed as a decimal)
applicable to such date by 360 for Commercial Paper Rate Notes, Prime Rate
Notes, LIBOR Notes, CD Rate Notes, or Federal Funds Rate Notes, or by the actual
number of days in the year for Treasury Rate Notes or CMT Rate Notes. Interest
on Fixed Rate Notes will be computed on the basis of a 360-day year of twelve
30-day months.
 
    A payment on any Fixed Rate Note due on any day that is not a Market Day
(and, for any Note denominated in other than U.S. dollars, a Business Day in the
country issuing the Specified Currency (or, for ECUs, Brussels)) need not be
made on such a day, but may be made on the next succeeding Market Day with the
same force and effect as if made on the due date, and no interest shall accrue
for the period from and after such date.
 
    Payment of the principal of (and premium, if any) and any interest due with
respect to any Note (other than a Book-Entry Note) at maturity will be made in
immediately available funds upon surrender of such Note at the Paying Agent
Office in The City of New York, provided that the Note is presented to the
Paying Agent in time for the Paying Agent to make such payments in such funds in
accordance with its normal procedures. Payments of interest on any Note (other
than any Book-Entry Note) other than at maturity will be made by check mailed to
the address of the Person (which, in the case of a permanent global Note
representing Book-Entry Notes, shall be the Depositary) entitled thereto as it
appears in the Security Register or by wire transfer to such account as may have
been appropriately designated by such Person. Payments in respect of Book-Entry
Notes are further discussed under "Book-Entry Notes."
 
    If the principal of (and premium, if any) or interest on any Note is payable
in other than U.S. dollars and such Specified Currency is not available due to
the imposition of exchange controls or other circumstances beyond the control of
the Company, the Company will be entitled to satisfy its obligations to Holders
of the Notes by making such payment in U.S. dollars on the basis of the most
recently available Exchange Rate. Any payment made under such circumstances in
U.S. dollars where the required payment is in other than U.S. dollars will not
constitute an Event of Default under the Indenture.
 
AMORTIZING NOTES
 
    The Company may from time to time offer Notes for which payments of
principal and interest are made over the life of the Notes ("Amortizing Notes").
Unless otherwise specified in the applicable Pricing Supplement, interest on
each Amortizing Note will be computed on the basis of a 360-day year of twelve
30-day months. Payments with respect to Amortizing Notes will be applied first
to interest due and payable thereon and then to the reduction of the unpaid
principal amount thereof. Further information concerning additional terms and
provisions of Amortizing Notes will be specified in the applicable Pricing
Supplement, including a table setting forth repayment information for such
Amortizing Notes.
 
BOOK-ENTRY NOTES
 
    Upon issuance, all Book-Entry Notes of like tenor and having the same date
of issue will be represented by a single permanent global Note. Each permanent
global Note representing Book-Entry Notes will be deposited with, or on behalf
of, The Depository Trust Company, as Depositary (the "Depositary"), located in
the Borough of Manhattan, The City of New York, and will be registered in the
name of the Depositary or a nominee of the Depositary. Currently, the Depositary
will accept the deposit of only permanent global Notes denominated in U.S.
dollars.
 
    Ownership of beneficial interests in a permanent global Note representing
Book-Entry Notes will be limited to institutions that have accounts with the
Depositary or its nominee ("participants") or persons that may hold interests
through participants. In addition, ownership of beneficial interests by
participants in such a permanent global Note will be evidenced only by, and the
transfer of that ownership interest will be effected only through, records
maintained by the Depositary or its nominee for such permanent global Note.
Ownership of beneficial interests in such a permanent global Note by persons
that hold
 
                                      S-13

through participants will be evidenced only by, and the transfer of that
ownership interest within such participant will be effected only through,
records maintained by such participant. The laws of some jurisdictions require
that certain purchasers of securities take physical delivery of such securities
in definitive form. Such laws may impair the ability to transfer beneficial
interests in such a permanent global Note.
 
    The Company has been advised by the Depositary that upon the issuance of a
permanent global Note representing Book-Entry Notes, and the deposit of such
permanent global Note with the Depositary, the Depositary will immediately
credit, on its book-entry registration and transfer system, the respective
principal amounts of the Book-Entry Notes represented by such permanent global
Note to the accounts of participants. The accounts to be credited shall be
designated by the soliciting Agent or, to the extent that the Book-Entry Notes
are offered and sold directly, by the Company.
 
    Payment of principal of and any premium and interest on Book-Entry Notes
represented by any permanent global Note registered in the name of or held by
the Depositary or its nominee will be made to the Depositary or its nominee, as
the case may be, as the registered owner and Holder of the permanent global Note
representing such Book-Entry Notes. Neither the Company, the Trustee, nor any
agent of the Company or the Trustee will have any responsibility or liability
for any aspect of the Depositary's records or any participant's records relating
to or payments made on account of beneficial ownership interests in a permanent
global Note representing such Book-Entry Notes or for maintaining, supervising
or reviewing any of the Depositary's records or any participant's records
relating to such beneficial ownership interests.
 
    The Company has been advised by the Depositary that upon receipt of any
payment of principal of or any premium or interest in respect of a permanent
global Note, the Depositary will immediately credit, on its book-entry
registration and transfer system, accounts of participants with payments in
amounts proportionate to their respective beneficial interests in the principal
amount of such permanent global Note as shown on the records of the Depositary.
Payments by participants to owners of beneficial interests in a permanent global
Note held through such participants will be governed by standing instructions
and customary practices, as is now the case with securities held for the
accounts of customers registered in "street name," and will be the sole
responsibility of such participants.
 
    No permanent global Note described above may be transferred except as a
whole by the Depositary for such permanent global Note to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary.
 
    A permanent global Note representing Book-Entry Notes is exchangeable for
definitive Notes registered in the name of, and a transfer of a permanent global
Note may be registered to, any Person other than the Depositary or its nominee,
only if:
 
       (a) the Depositary notifies the Company that it is unwilling or unable to
           continue as Depositary for such permanent global Note or if at any
    time the Depositary ceases to be a clearing agency registered under the
    Securities Exchange Act of 1934, as amended (the "Exchange Act");
 
       (b) the Company in its sole discretion determines that such permanent
           global Note shall be exchangeable for definitive Notes in registered
    form; or
 
       (c) any event shall have happened and be continuing that constitutes or,
           after notice or lapse of time, or both, would constitute an Event of
    Default with respect to the Notes.
 
    Any permanent global Note that is exchangeable pursuant to the preceding
    sentence shall be exchangeable in whole for definitive Notes in registered
    form, of like tenor and of an equal aggregate principal amount, in
    denominations of U.S. $1,000 and integral multiples of U.S. $1,000 in excess
    thereof. Such definitive Notes shall be registered in the name or names of
    such person or persons as the Depositary shall instruct the Trustee. It is
    expected that such instructions may be based upon directions received by the
    Depositary from its participants with respect to ownership of beneficial
    interests in such permanent global Note.
 
                                      S-14

    Except as provided above, owners of beneficial interests in such permanent
global Note will not be entitled to receive physical delivery of Notes in
definitive form and will not be considered the Holders thereof for any purpose
under the Indenture, and no permanent global Note representing Book-Entry Notes
shall be exchangeable, except for another permanent global Note of like
denomination and tenor to be registered in the name of the Depositary or its
nominee. Accordingly, each person owning a beneficial interest in such permanent
global Note must rely on the procedures of the Depositary and, if such person is
not a participant, on the procedures of the participant through which such
person owns its interest, to exercise any rights of a Holder under the
Indenture.
 
    The Indenture provides that the Depositary, as a Holder, may appoint agents
and otherwise authorize participants to give or take any request, demand,
authorization, direction, notice, consent, waiver, or other action which a
Holder is entitled to give or take under the Indenture. The Company understands
that, under existing industry practices, in the event that the Company requests
any action of Holders or an owner of a beneficial interest in such permanent
global Note desires to give or take any action that a Holder is entitled to give
or take under the Indenture, the Depositary would authorize the participants
holding the relevant beneficial interests to give or take such action, and such
participants would authorize beneficial owners owning through such participants
to give or take such action or would otherwise act upon the instructions of
beneficial owners owning through them.
 
    The Depositary has advised the Company that the Depositary is a limited
purpose trust company organized under the laws of the State of New York, a
member of the Federal Reserve System, a "clearing corporation" within the
meaning of the New York Uniform Commercial Code, and a "clearing agency"
registered under the Exchange Act. The Depositary was created to hold securities
of its participants and to facilitate the clearance and settlement of securities
transactions among its participants in such securities through electronic
book-entry changes in accounts of the participants, thereby eliminating the need
for physical movement of securities certificates. The Depositary's participants
include securities brokers and dealers (including the Agents), banks, trust
companies, clearing corporations, and certain other organizations, some of whom
(or their representatives) own the Depositary. Access to the Depositary's
book-entry system is also available to others, such as banks, brokers, dealers
and trust companies that clear through or maintain a custodial relationship with
a participant, either directly or indirectly.
 
REGARDING THE PAYING AGENT
 
    The Paying Agent maintains a banking relationship with, and may make loans
to, the Company.
 
REPAYMENT AT THE OPTION OF THE HOLDER
 
    The Notes will be repayable by the Company at the option of the Holders
thereof prior to Stated Maturity only if one or more optional repayment dates
are specified in the applicable Pricing Supplement ("Optional Repayment Dates").
If so specified, the Notes will be subject to repayment at the option of the
Holders thereof on any Optional Repayment Date in whole or from time to time in
part in increments of $1,000 or such other minimum denomination specified in the
applicable Pricing Supplement (provided that any remaining principal amount
thereof shall be at least $1,000 or such other minimum denomination), at a
repayment price equal to 100% of the unpaid principal amount to be repaid (or,
if this Note is an Original Issue Discount Note, such lesser amount as provided
therein), together with unpaid interest accrued to the date of repayment. For
any Note to be repaid, such Note must be received, together with the form
thereon entitled "Option to Elect Repayment" duly completed, by the Trustee at
its Corporate Trust Office (or such other address of which the Company shall
from time to time notify the Holders) not more than 60 nor less than 30 calendar
days prior to the date of repayment. Exercise of such repayment option by the
Holder will be irrevocable.
 
    Only the Depositary may exercise the repayment option in respect of Global
Securities representing Book-Entry Notes. Accordingly, holders of beneficial
interests ("Beneficial Owners") of a permanent global Note that desire to have
all or any portion of the Book-Entry Notes represented by such permanent global
Note repaid must instruct the participant through which they own their interest
to direct the Depositary to exercise the repayment option on their behalf by
delivering the related permanent global Note and duly completed election form to
the Trustee as aforesaid. In order to ensure that such
 
                                      S-15

permanent global Note and election form are received by the Trustee on a
particular day, the applicable Beneficial Owner must so instruct the participant
through which it owns its interest before such participant's deadline for
accepting instructions for that day. Different firms may have different
deadlines for accepting instructions from their customers. Accordingly,
Beneficial Owners should consult the participants through which they own their
interest for the respective deadlines for such participants. All instructions
given to participants from Beneficial Owners of permanent global Notes relating
to the option to elect repayment shall be irrevocable. In addition, at the time
such instructions are given, each such Beneficial Owner shall cause the
participant through which it owns its interest to transfer such Beneficial
Owner's interest in the permanent global Note or Notes representing the related
Book-Entry Notes, on the Depositary's records, to the Trustee. See "Book-Entry
Notes."
 
    If applicable, the Company will comply with the requirements of Rule 14c-1
under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and
any other securities laws or regulations in connection with any such repayment.
 
    The Company may at any time purchase Notes at any price or prices in the
open market or otherwise. Notes so purchased by the Company may, at the
discretion of the Company, be held, resold or surrendered to the Trustee for
cancellation.
 
OPTIONAL REDEMPTION
 
    Unless otherwise specified in the applicable Pricing Supplement, the Notes
will not be redeemable prior to their Stated Maturity. If so specified in the
applicable Pricing Supplement, the Notes will be redeemable at the option of the
Company at any time after the date or dates specified therein. If one or more
such dates are so specified with respect to any Note, the applicable Pricing
Supplement will also specify one or more redemption prices (expressed as a
percentage of the principal amount of such Note) ("Redemption Prices") and the
redemption period or periods ("Redemption Periods") during which such Redemption
Prices shall apply. Unless otherwise specified in the Pricing Supplement, any
such Note shall be redeemable at the option of the Company at the specified
Redemption Price applicable to the Redemption Period during which such Note is
to be redeemed, together with interest accrued to the Redemption Date.
 
    If so specified in the applicable Pricing Supplement, the Notes will be
redeemable at the Company's option, as a whole or from time to time in part, on
any date prior to their Stated Maturity at a Redemption Price equal to 100% of
the principal amount thereof plus accrued interest to the Redemption Date
(subject to the right of Holders of record on the relevant Regular Record Date
to receive interest due on an Interest Payment Date that is on or prior to the
Redemption Date), plus a Make-Whole Premium, if any.
 
    The "Make-Whole Premium" in respect of any Note is intended to be the
amount, if any, which, when added to the then outstanding principal amount of
such Note, would, if invested on the Redemption Date of such Note in U.S.
Treasury securities with maturities equal to the Remaining Life of the Notes,
have a yield to maturity equal to the original yield to maturity of the Notes,
based on the initial public offering price of the Notes set forth in the
applicable Pricing Supplement. The amount of the Make-Whole Premium in respect
of the principal amount of any Note to be redeemed will be the excess, if any,
of (i) the sum of the present values, as of the Redemption Date of such Note, of
(A) the respective interest payments (exclusive of the amount of accrued
interest to the Redemption Date) on such Note that, but for such redemption,
would have been payable on their respective Interest Payment Dates after such
Redemption Date, and (B) the payment of such principal amount that, but for such
redemption, would have been payable on the Stated Maturity over (ii) the amount
of such principal to be redeemed. Such present values will be determined in
accordance with generally accepted principals of financial analysis by
discounting the amounts of such payments of interest and principal from their
respective Stated Maturities to such Redemption Date at a discount rate equal to
the Treasury Yield.
 
    The "Treasury Yield" in respect of any Note to be redeemed shall be
determined as of the date on which notice of redemption of such Note is sent to
the Holder thereof by reference to the most recent Federal Reserve Statistical
Release H.15 (519) (or successor publication) which has become publicly
 
                                      S-16

available not more than two Business Days prior to such date (or, if such
Statistical Release (or successor publication) is no longer published or no
longer contains the applicable data, to the most recently published issue of THE
WALL STREET JOURNAL (EASTERN EDITION) published not more than two Business Days
prior to such date that contains such data or, if THE WALL STREET JOURNAL
(EASTERN EDITION) is no longer published or no longer contains such data, to any
publicly available source of similar market data), and shall be the most recent
weekly average yield on actively traded U.S. Treasury securities adjusted to a
constant maturity equal to the Remaining Life of the Notes and, if applicable,
converted to a bond equivalent yield basis as described below. The "Remaining
Life of the Notes" shall equal the number of years from the Redemption Date to
the Stated Maturity of the Notes; PROVIDED that if the Remaining Life of the
Notes being redeemed is not equal to the constant maturity of a U.S. Treasury
security for which a weekly average yield is specified in the applicable source,
then the Remaining Life of the Notes shall be rounded to the nearest one-twelfth
of one year and the Treasury Yield shall be obtained by linear interpolation
(computed to the fifth decimal place (one thousandth of a percentage point) and
then rounded to the fourth decimal place (one hundredth of a percentage point)),
after rounding to the nearest one-twelfth of one year, from the weekly average
yields of (a) the actively traded U.S. Treasury security with a maturity closest
to and less than the Remaining Life of the Notes and (b) the actively traded
U.S. Treasury security with a maturity closest to and greater than the Remaining
Life of the Notes, except that if the Remaining Life of the Notes is less than
three months, the weekly average yield on actively traded U.S. Treasury
securities adjusted to a constant maturity of three months shall be used. The
Treasury Yield shall, if expressed on a yield basis other than that equivalent
to a bond equivalent yield basis, be converted to a bond equivalent yield basis
and shall be computed to the fifth decimal place (one thousandth of a percentage
point) and then rounded to the fourth decimal place (one hundredth of a
percentage point).
 
    Notice of redemption will be provided by mailing a notice of such redemption
to each Holder by first class mail, postage prepaid, at least 30 days and not
more than 60 days prior to the date fixed for redemption to the respective
address of each Holder as that address appears in the Security Register.
 
    The Company may purchase Notes at any price in the open market or otherwise.
Notes so purchased by the Company may, at the discretion of the Company, be held
or resold or surrendered to the Trustee for cancellation.
 
                             UNITED STATES TAXATION
 
    The following discussion is a summary of the principal United States federal
income tax consequences of ownership and disposition of Notes. It deals only
with Notes held as capital assets by initial purchasers and not with special
classes of holders, such as dealers in securities or currencies, banks,
tax-exempt organizations, life insurance companies, persons that hold Notes that
are a hedge or that are hedged against currency risks or that are part of a
straddle or conversion transaction or persons whose functional currency is not
the U.S. dollar. Moreover, the summary deals only with Notes that are due to
mature 30 years or less from the date on which they are issued. The United
States federal income tax consequences of ownership of Notes that are due to
mature more than 30 years from their date of issue will be discussed in an
applicable Pricing Supplement. The summary is based on the Internal Revenue Code
of 1986, as amended (the "Code"), its legislative history, existing and proposed
regulations thereunder, published rulings and court decisions, all as currently
in effect and all subject to change at any time, perhaps with retroactive
effect.
 
    Prospective purchasers of Notes should consult their own tax advisors
concerning the consequences, in their particular circumstances, under the Code
and the laws of any other taxing jurisdiction, of the ownership and disposition
of Notes.
 
UNITED STATES HOLDERS
 
PAYMENTS OF INTEREST
 
    Interest on a Note, whether payable in U.S. dollars or a currency, composite
currency or basket of currencies other than U.S. dollars (a "foreign currency"),
other than interest on a "Discount Note" that is
 
                                      S-17

not "qualified stated interest" (each as defined below under "Original Issue
Discount -- General"), will be taxable to a United States Holder as ordinary
income at the time it is received or accrued, depending on the holder's method
of accounting for tax purposes. A United States Holder is a beneficial owner who
or that is (i) a citizen or resident of the United States, (ii) a domestic
corporation or (iii) otherwise subject to United States federal income taxation
on a net income basis in respect of a Note.
 
    If an interest payment is denominated in, or determined by reference to, a
foreign currency, the amount of income recognized by a cash basis United States
Holder will be the U.S. dollar value of the interest payment, based on the
exchange rate in effect on the date of receipt, regardless of whether the
payment is in fact converted into U.S. dollars.
 
    An accrual basis United States Holder may determine the amount of income
recognized with respect to an interest payment denominated in, or determined by
reference to, a foreign currency in accordance with either of two methods. Under
the first method, the amount of income accrued will be based on the average
exchange rate in effect during the interest accrual period (or, with respect to
an accrual period that spans two taxable years, the part of the period within
the taxable year).
 
    Under the second method, the United States Holder may elect to determine the
amount of income accrued on the basis of the exchange rate in effect on the last
day of the accrual period or, in the case of an accrual period that spans two
taxable years, the exchange rate in effect on the last day of the part of the
period within the taxable year. Additionally, if a payment of interest is
actually received within five business days of the last day of the accrual
period or taxable year, an electing accrual basis United States Holder may
instead translate such accrued interest into U.S. dollars at the exchange rate
in effect on the day of actual receipt. Any such election will apply to all debt
instruments held by the United States Holder at the beginning of the first
taxable year to which the election applies or thereafter acquired by the United
States Holder, and will be irrevocable without the consent of the Internal
Revenue Service (the "Service").
 
    Upon receipt of the interest payment (including a payment attributable to
accrued but unpaid interest upon the sale or retirement of a Note) denominated
in, or determined by reference to, a foreign currency, the United States Holder
will recognize ordinary income or loss measured by the difference between (x)
the average exchange rate used to accrue interest income, or the exchange rate
as determined under the second method described above if the United States
Holder elects that method, and (y) the exchange rate in effect on the date of
receipt, regardless of whether the payment is in fact converted into U.S.
dollars.
 
ORIGINAL ISSUE DISCOUNT
 
    GENERAL.  A Note, other than a Note with a term of one year or less (a
"short-term Note"), will be treated as issued at an original issue discount (a
"Discount Note") if the excess of the Note's "stated redemption price at
maturity" over its issue price is more than a "de minimis amount" (as defined
below). Generally, the issue price of a Note will be the first price at which a
substantial amount of Notes included in the issue of which the Note is a part is
sold to other than bond houses, brokers, or similar persons or organizations
acting in the capacity of underwriters, placement agents, or wholesalers. The
stated redemption price at maturity of a Note is the total of all payments
provided by the Note that are not payments of "qualified stated interest". A
qualified stated interest payment is generally any one of a series of stated
interest payments on a Note that are unconditionally payable at least annually
at a single fixed rate (with certain exceptions for lower rates paid during some
periods) applied to the outstanding principal amount of the Note. Special rules
for "Variable Rate Notes" (as defined below under "Original Issue Discount --
Variable Rate Notes") are described below under "Original Issue Discount --
Variable Rate Notes."
 
    In general, if the excess of a Note's stated redemption price at maturity
over its issue price is less than 1/4 of 1 percent of the Note's stated
redemption price at maturity multiplied by the number of complete years to its
maturity (the "de minimis amount"), then such excess, if any, constitutes "de
minimis original issue discount" and the Note is not a Discount Note. Unless the
election described
 
                                      S-18

below under "Election to Treat All Interest as Original Issue Discount" is made,
a United States Holder of a Note with de minimis original issue discount must
include such de minimis original issue discount in income as stated principal
payments on the Note are made. The includible amount with respect to each such
payment will equal the product of the total amount of the Note's de minimis
original issue discount and a fraction, the numerator of which is the amount of
the principal payment made and the denominator of which is the stated principal
amount of the Note.
 
    United States Holders of Discount Notes having a maturity of more than one
year from their date of issue must, generally, include original issue discount
("OID") in income calculated on a constant-yield method before the receipt of
cash attributable to such income. The amount of OID includible in income by a
United States Holder of a Discount Note is the sum of the daily portions of OID
with respect to the Discount Note for each day during the taxable year or
portion of the taxable year on which the United States Holder holds such
Discount Note ("accrued OID"). The daily portion is determined by allocating to
each day in any "accrual period" a pro rata portion of the OID allocable to that
accrual period. Accrual periods with respect to a Note may be of any length
selected by the United States Holder and may vary in length over the term of the
Note as long as (i) no accrual period is longer than one year and (ii) each
scheduled payment of interest or principal on the Note occurs on either the
final or first day of an accrual period. The amount of OID allocable to an
accrual period equals the excess of (a) the product of the Discount Note's
adjusted issue price at the beginning of the accrual period and such Note's
yield to maturity (determined on the basis of compounding at the close of each
accrual period and properly adjusted for the length of the accrual period) over
(b) the sum of the payments of qualified stated interest on the Note allocable
to the accrual period. The "adjusted issue price" of a Discount Note at the
beginning of any accrual period is the issue price of the Note increased by (x)
the amount of accrued OID for each prior accrual period and decreased by (y) the
amount of any payments previously made on the Note that were not qualified
stated interest payments. For purposes of determining the amount of OID
allocable to an accrual period, if an interval between payments of qualified
stated interest on the Note contains more than one accrual period, the amount of
qualified stated interest payable at the end of the interval (including any
qualified stated interest that is payable on the first day of the accrual period
immediately following the interval) is allocated pro rata on the basis of
relative lengths to each accrual period in the interval, and the adjusted issue
price at the beginning of each accrual period in the interval must be increased
by the amount of any qualified stated interest that has accrued prior to the
first day of the accrual period but that is not payable until the end of the
interval. The amount of OID allocable to an initial short accrual period may be
computed using any reasonable method if all other accrual periods other than a
final short accrual period are of equal length. The amount of OID allocable to
the final accrual period is the difference between (x) the amount payable at the
maturity of the Note (other than any payment of qualified stated interest) and
(y) the Note's adjusted issue price as of the beginning of the final accrual
period.
 
    ACQUISITION PREMIUM.  A United States Holder that purchases a Note for an
amount less than or equal to the sum of all amounts payable on the Note after
the purchase date other than payments of qualified stated interest but in excess
of its adjusted issue price (as determined above under "Original Issue Discount
- -- General") (any such excess being "acquisition premium") and that does not
make the election described below under "Election to Treat All Interest as
Original Issue Discount" is permitted to reduce the daily portions of OID by a
fraction, the numerator of which is the excess of the United States Holder's
adjusted basis in the Note immediately after its purchase over the adjusted
issue price of the Note, and the denominator of which is the excess of the sum
of all amounts payable on the Note after the purchase date, other than payments
of qualified stated interest, over the Note's adjusted issue price.
 
    MARKET DISCOUNT.  A Note, other than a short-term Note, will be treated as
purchased at a market discount (a "Market Discount Note") if (i) the amount for
which a United States Holder purchased the Note is less than the Note's issue
price (as determined above under "Original Issue Discount -- General") and (ii)
the Note's stated redemption price at maturity or, in the case of a Discount
Note, the Note's "revised issue price", exceeds the amount for which the United
States Holder purchased the Note by at least 1/4 of 1 percent of such Note's
stated redemption price at maturity or revised issue price,
 
                                      S-19

respectively, multiplied by the number of complete years to the Note's maturity.
If such excess is not sufficient to cause the Note to be a Market Discount Note,
then such excess constitutes "de minimis market discount" and such Note is not
subject to the rules discussed in the following paragraphs. The Code provides
that, for these purposes, the "revised issue price" of a Note generally equals
its issue price, increased by the amount of any OID that has accrued on the
Note.
 
    Any gain recognized on the maturity or disposition of a Market Discount Note
will be treated as ordinary income to the extent that such gain does not exceed
the accrued market discount on such Note. Alternatively, a United States Holder
of a Market Discount Note may elect to include market discount in income
currently over the life of the Note. Such an election shall apply to all debt
instruments with market discount acquired by the electing United States Holder
on or after the first day of the first taxable year to which the election
applies. This election may not be revoked without the consent of the Service.
 
    Market discount on a Market Discount Note will accrue on a straight-line
basis unless the United States Holder elects to accrue such market discount on a
constant-yield method. Such an election shall apply only to the Note with
respect to which it is made and may not be revoked. A United States Holder of a
Market Discount Note that does not elect to include market discount in income
currently generally will be required to defer deductions for interest on
borrowings allocable to such Note in an amount not exceeding the accrued market
discount on such Note until the maturity or disposition of such Note.
 
    PRE-ISSUANCE ACCRUED INTEREST.  If (i) a portion of the initial purchase
price of a Note is attributable to pre-issuance accrued interest, (ii) the first
stated interest payment on the Note is to be made within one year of the Note's
issue date and (iii) the payment will equal or exceed the amount of pre-issuance
accrued interest, then the United States Holder may elect to decrease the issue
price of the Note by the amount of pre-issuance accrued interest. In that event,
a portion of the first stated interest payment will be treated as a return of
the excluded pre-issuance accrued interest and not as an amount payable on the
Note.
 
    NOTES SUBJECT TO CONTINGENCIES INCLUDING OPTIONAL REDEMPTION.  In general,
if a Note provides for an alternative payment schedule or schedules applicable
upon the occurrence of a contingency or contingencies (other than a remote or
incidental contingency), the timing and amounts of the payments that comprise
each payment schedule are known as of the issue date and one of such schedules
is significantly more likely than not to occur, the yield and maturity of the
Note are determined by assuming that the payments will be made according to that
payment schedule. If there is no single payment schedule that is significantly
more likely than not to occur (other than because of a mandatory sinking fund),
the Note will be subject to special rules governing contingent payment
obligations that will be discussed in the applicable Pricing Supplement.
 
    Notwithstanding the general rules for determining yield and maturity in the
case of Notes subject to contingencies, if the Company or the Holder has an
unconditional option or options that, if exercised, would require payments to be
made on the Note under an alternative payment schedule or schedules, then (i) in
the case of an option or options of the Company, the Company will be deemed to
exercise or not exercise an option or combination of options in the manner that
minimizes the yield on the Note and (ii) in the case of an option or options of
the Holder, the Holder will be deemed to exercise or not exercise an option or
combination of options in the manner that maximizes the yield on the Note. If
both the Company and the Holder have options described in the preceding
sentence, those rules apply to such options in the order in which they may be
exercised. For purposes of those calculations, the yield on the Note is
determined by using any date on which the Note may be redeemed or repurchased as
the maturity date and the amount payable on such date in accordance with the
terms of the Note as the principal amount payable at maturity.
 
    If a contingency (including the exercise of an option) actually occurs or
does not occur contrary to an assumption made according to the above rules (a
"change in circumstances") then, except to the extent that a portion of the Note
is repaid as a result of the change in circumstances and solely for
 
                                      S-20

purposes of determining the amount and accrual of OID, the yield and maturity of
the Note are redetermined by treating the Note as having been retired and
reissued on the date of the change in circumstances for an amount equal to the
Note's adjusted issue price on that date.
 
    ELECTION TO TREAT ALL INTEREST AS ORIGINAL ISSUE DISCOUNT.  A United States
Holder may elect to include in gross income all interest that accrues on a Note
using the constant-yield method described above under the heading "Original
Issue Discount -- General", with the modifications described below. For purposes
of this election, interest includes stated interest, OID, de minimis original
issue discount, market discount, de minimis market discount and unstated
interest, as adjusted by any amortizable bond premium (described below under
"Notes Purchased at a Premium") or acquisition premium.
 
    In applying the constant-yield method to a Note with respect to which this
election has been made, the issue price of the Note will equal its cost to the
electing United States Holder, the issue date of the Note will be the date of
its acquisition by the electing United States Holder, and no payments on the
Note will be treated as payments of qualified stated interest. This election
will generally apply only to the Note with respect to which it is made and may
not be revoked without the consent of the Service. If this election is made with
respect to a Note with amortizable bond premium, then the electing United States
Holder will be deemed to have elected to apply amortizable bond premium against
interest with respect to all debt instruments with amortizable bond premium
(other than debt instruments the interest on which is excludible from gross
income) held by the electing United States Holder as of the beginning of the
taxable year in which the Note with respect to which the election is made is
acquired or thereafter acquired. The deemed election with respect to amortizable
bond premium may not be revoked without the consent of the Service.
 
    If the election to apply the constant-yield method to all interest on a Note
is made with respect to a Market Discount Note, the electing United States
Holder will be treated as having made the election discussed above under
"Original Issue Discount -- Market Discount" to include market discount in
income currently over the life of all debt instruments held or thereafter
acquired by such United States Holder.
 
    VARIABLE RATE NOTES.  A "Variable Rate Note" is a Note that: (i) has an
issue price that does not exceed the total noncontingent principal payments by
more than the lesser of (1) the product of (x) the total noncontingent principal
payments, (y) the number of complete years to maturity from the issue date and
(z) .015, or (2) 15 percent of the total noncontingent principal payments, and
(ii) does not provide for stated interest other than stated interest compounded
or paid at least annually at (1) one or more "qualified floating rates", (2) a
single fixed rate and one or more qualified floating rates, (3) a single
"objective rate" or (4) a single fixed rate and a single objective rate that is
a "qualified inverse floating rate."
 
    A qualified floating rate or objective rate in effect at any time during the
term of the instrument must be set at a "current value" of that rate. A "current
value" of a rate is the value of the rate on any day that is no earlier than 3
months prior to the first day on which that value is in effect and no later than
1 year following that first day.
 
    A variable rate is a "qualified floating rate" if (i) variations in the
value of the rate can reasonably be expected to measure contemporaneous
variations in the cost of newly borrowed funds in the currency in which the Note
is denominated or (ii) it is equal to the product of such a rate and either (a)
a fixed multiple that is greater than 0.65 but not more than 1.35, or (b) a
fixed multiple greater than 0.65 but not more than 1.35, increased or decreased
by a fixed rate. If a Note provides for two or more qualified floating rates
that (i) are within 0.25 percent of each other on the issue date or (ii) can
reasonably be expected to have approximately the same values throughout the term
of the Note, the qualified floating rates together constitute a single qualified
floating rate. A rate is not a qualified floating rate, however, if the rate is
subject to certain restrictions (including caps, floors, governors, or other
similar restrictions) unless such restrictions are fixed throughout the term of
the Note or are not reasonably expected to significantly affect the yield on the
Note.
 
                                      S-21

    An "objective rate" is a rate, other than a qualified floating rate, that is
determined using a single, fixed formula and that is based on objective
financial or economic information that is not within the control of or unique to
the circumstances of the issuer or a related party. A variable rate is not an
objective rate, however, if it is reasonably expected that the average value of
the rate during the first half of the Note's term will be either significantly
less than or significantly greater than the average value of the rate during the
final half of the Note's term. An objective rate is a "qualified inverse
floating rate" if (i) the rate is equal to a fixed rate minus a qualified
floating rate, and (ii) the variations in the rate can reasonably be expected to
inversely reflect contemporaneous variations in the cost of newly borrowed
funds.
 
    If interest on a Note is stated at a fixed rate for an initial period of one
year or less followed by either a qualified floating rate or an objective rate
for a subsequent period and (i) the fixed rate and the qualified floating rate
or objective have values on the issue date of the Note that do not differ by
more than 0.25 percent or (ii) the value of the qualified floating rate or
objective rate is intended to approximate the fixed rate, the fixed rate and the
qualified floating rate or the objective rate constitute a single qualified
floating rate or objective rate. Under these rules, Commercial Paper Rate Notes,
Prime Rate Notes, LIBOR Notes, Treasury Rate Notes, CD Rate Notes, CMT Rate
Notes and Federal Funds Rate Notes will generally be treated as Variable Rate
Notes.
 
    In general, if a Variable Rate Note provides for stated interest at a single
qualified floating rate or objective rate, all stated interest on the Note is
qualified stated interest and the amount of OID, if any, is determined by using,
in the case of a qualified floating rate or qualified inverse floating rate, the
value as of the issue date of the qualified floating rate or qualified inverse
floating rate, or, in the case of any other objective rate, a fixed rate that
reflects the yield reasonably expected for the Note.
 
    If a Variable Rate Note does not provide for stated interest at a single
qualified floating rate or a single objective rate and also does not provide for
interest payable at a fixed rate (other than at a single fixed rate for an
initial period), the amount of interest and OID accruals on the Note are
generally determined by (i) determining a fixed rate substitute for each
variable rate provided under the Variable Rate Note (generally, the value of
each variable rate as of the issue date or, in the case of an objective rate
that is not a qualified inverse floating rate, a rate that reflects the
reasonably expected yield on the Note), (ii) constructing the equivalent fixed
rate debt instrument (using the fixed rate substitutes described above), (iii)
determining the amount of qualified stated interest and OID with respect to the
equivalent fixed rate debt instrument, and (iv) making the appropriate
adjustments for actual variable rates during the applicable accrual period.
 
    If a Variable Rate Note provides for stated interest either at one or more
qualified floating rates or at a qualified inverse floating rate, and in
addition provides for stated interest at a single fixed rate (other than at a
single fixed rate for an initial period), the amount of interest and OID
accruals are determined as in the immediately preceding paragraph with the
modification that the Variable Rate Note is treated, for purposes of the first
three steps of the determination, as if it provided for a qualified floating
rate (or a qualified inverse floating rate, as the case may be) rather than the
fixed rate. The qualified floating rate (or qualified inverse floating rate)
replacing the fixed rate must be such that the fair market value of the Variable
Rate Note as of the issue date would be approximately the same as the fair
market value of an otherwise identical debt instrument that provides for the
qualified floating rate (or qualified inverse floating rate) rather than the
fixed rate.
 
    SHORT-TERM NOTES.  In general, an individual or other cash basis United
States Holder of a short-term Note is not required to accrue OID (as specially
defined below for the purposes of this paragraph) for United States federal
income tax purposes unless it elects to do so (but may be required to include
any stated interest in income as the interest is received). Accrual basis United
States Holders and certain other United States Holders, including banks,
regulated investment companies, dealers in securities, common trust funds,
United States Holders who hold Notes as part of certain identified hedging
transactions, certain pass-through entities and cash basis United States Holders
who so elect, are required to accrue OID on short-term Notes on either a
straight-line basis or under the constant-yield
 
                                      S-22

method (based on daily compounding), at the election of the United States
Holder. In the case of a United States Holder not required and not electing to
include OID in income currently, any gain realized on the sale or retirement of
the short-term Note will be ordinary income to the extent of the OID accrued on
a straight-line basis (unless an election is made to accrue the OID under the
constant-yield method) through the date of sale or retirement. United States
Holders who are not required and do not elect to accrue OID on short-term Notes
will be required to defer deductions for interest on borrowings allocable to
short-term Notes in an amount not exceeding the deferred income until the
deferred income is realized.
 
    For purposes of determining the amount of OID subject to these rules, all
interest payments on a short-term Note, including stated interest, are included
in the short-term Note's stated redemption price at maturity.
 
    FOREIGN CURRENCY DISCOUNT NOTES.  OID for any accrual period on a Discount
Note that is denominated in, or determined by reference to, a foreign currency
will be determined in the foreign currency and then translated into U.S. dollars
in the same manner as stated interest accrued by an accrual basis United States
Holder, as described under "Payments of Interest." Upon receipt of an amount
attributable to OID (whether in connection with a payment of interest or the
sale or retirement of a Note), a United States Holder may recognize ordinary
income or loss.
 
NOTES PURCHASED AT A PREMIUM
 
    A United States Holder that purchases a Note for an amount in excess of its
principal amount may elect to treat such excess as "amortizable bond premium",
in which case the amount required to be included in the United States Holder's
income each year with respect to interest on the Note will be reduced by the
amount of amortizable bond premium allocable (based on the Note's yield to
maturity) to such year. In the case of a Note that is denominated in, or
determined by reference to, a foreign currency, amortizable bond premium will be
computed in units of foreign currency, and amortizable bond premium will reduce
interest income in units of the foreign currency. At the time amortized bond
premium offsets interest income, exchange gain or loss (taxable as ordinary
income or loss) is realized measured by the difference between exchange rates at
that time and at the time of the acquisition of the Notes. Any election to
amortize bond premium shall apply to all bonds (other than bonds the interest on
which is excludible from gross income) held by the United States Holder at the
beginning of the first taxable year to which the election applies or thereafter
acquired by the United States Holder, and is irrevocable without the consent of
the Service. See also "Original Issue Discount -- Election to Treat All Interest
as Original Issue Discount."
 
PURCHASE, SALE AND RETIREMENT OF THE NOTES
 
    A United States Holder's tax basis in a Note will generally be its U.S.
dollar cost (as defined below), increased by the amount of any OID or market
discount included in the United States Holder's income with respect to the Note
and the amount, if any, of income attributable to de minimis original issue
discount and de minimis market discount included in the United States Holder's
income with respect to the Note, and reduced by (i) the amount of any payments
that are not qualified stated interest payments, and (ii) the amount of any
amortizable bond premium applied to reduce interest on the Note. The U.S. dollar
cost of a Note purchased with a foreign currency will generally be the U.S.
dollar value of the purchase price on the date of purchase or, in the case of
Notes traded on an established securities market, as defined in the applicable
Treasury Regulations, that are purchased by a cash basis United States Holder
(or an accrual basis United States Holder that so elects), on the settlement
date for the purchase.
 
    A United States Holder will generally recognize gain or loss on the sale or
retirement of a Note equal to the difference between the amount realized on the
sale or retirement and the tax basis of the Note. The amount realized on a sale
or retirement for an amount in foreign currency will be the U.S. dollar value of
such amount on (i) the date payment is received in the case of a cash basis
United States Holder, (ii) the date of disposition in the case of an accrual
basis United States Holder or (iii) in the case of Notes traded on an
established securities market, as defined in the applicable Treasury
Regulations, sold by a cash
 
                                      S-23

basis United States Holder (or an accrual basis United States Holder that so
elects), on the settlement date for the sale. Except to the extent described
above under "Original Issue Discount -- Short-Term Notes" or "Original Issue
Discount -- Market Discount" or described in the next succeeding paragraph or
attributable to accrued but unpaid interest or with respect certain contingent
payment obligations, gain or loss recognized on the sale or retirement of a Note
will be capital gain or loss and will be long-term capital gain or loss if the
Note was held for more than one year.
 
    Gain or loss recognized by a United States Holder on the sale or retirement
of a Note that is attributable to changes in exchange rates will be treated as
ordinary income or loss. However, exchange gain or loss is taken into account
only to the extent of total gain or loss realized on the transaction.
 
EXCHANGE OF AMOUNTS IN OTHER THAN U.S. DOLLARS
 
    Foreign currency received as interest on a Note or on the sale or retirement
of a Note will have a tax basis equal to its U.S. dollar value at the time such
interest is received or at the time of such sale or retirement. Foreign currency
that is purchased will generally have a tax basis equal to the U.S. dollar value
of the foreign currency on the date of purchase. Any gain or loss recognized on
a sale or other disposition of a foreign currency (including its use to purchase
Notes or upon exchange for U.S. dollars) will be ordinary income or loss.
 
INDEXED NOTES, OTHER NOTES SUBJECT TO THE CONTINGENT PAYMENT RULES AND
AMORTIZING NOTES
 
    The applicable Pricing Supplement will contain a discussion of any special
United States federal income tax rules with respect to Notes that are not
subject to the rules governing Variable Rate Notes, payments on which are
determined by reference to any index, and with respect to other Notes subject to
the contingent payment rules and any Amortizing Notes.
 
UNITED STATES ALIEN HOLDERS
 
    For purposes of this discussion, a "United States Alien Holder" is any
holder of a Note who is (i) a nonresident alien individual or (ii) a foreign
corporation, partnership or estate or trust, in either case not subject to
United States federal income tax on a net income basis in respect of income or
gain from a Note. This discussion assumes that the Note is not subject to the
rules of Section 871(h)(4)(A) of the Code (relating to interest payments that
are determined by reference to the income, profits, changes in the value of
property or other attributes of the debtor or a related party).
 
    Under present United States federal income and estate tax law, and subject
to the discussion of backup withholding below:
 
           (i)
           payments of principal, premium (if any) and interest, including OID,
           by the Company or any of its paying agents to any holder of a Note
    that is a United States Alien Holder will not be subject to United States
    federal withholding tax if, in the case of interest or OID, (a) the
    beneficial owner of the Note does not actually or constructively own 10% or
    more of the total combined voting power of all classes of stock of the
    Company entitled to vote, (b) the beneficial owner of the Note is not a
    controlled foreign corporation that is related to the Company through stock
    ownership, and (c) either (A) the beneficial owner of the Note certifies to
    the Company or its agent, under penalties of perjury, that it is not a
    United States Holder and provides its name and address or (B) a securities
    clearing organization, bank or other financial institution that holds
    customers' securities in the ordinary course of its trade or business (a
    "financial institution") and holds the Note certifies to the Company or its
    agent under penalties of perjury that such statement has been received from
    the beneficial owner by it or by a financial institution between it and the
    beneficial owner and furnishes the payor with a copy thereof;
 
          (ii)
           a United States Alien Holder of a Note will not be subject to United
           States federal withholding tax on any gain realized on the sale or
    exchange of a Note; and
 
         (iii)
           a Note held by an individual who at death is not a citizen or
           resident of the United States will not be includible in the
    individual's gross estate for purposes of the United States federal estate
    tax as a result of the individual's death if (a) the individual did not
    actually or constructively own 10% or
 
                                      S-24

    more of the total combined voting power of all classes of stock of the
    Company entitled to vote and (b) the income on the Note would not have been
    effectively connected with a United States trade or business of the
    individual at the individual's death.
 
    Recently proposed Internal Revenue Service Treasury regulations (the
"Proposed Regulations") would provide alternative methods for satisfying the
certification requirement described in clause (i)(c) above. The Proposed
Regulations also would require, in the case of Notes held by a foreign
partnership, that (x) the certification described in clause (i)(c) above be
provided by the partners rather than by the foreign partnership and (y) the
partnership provide certain information, including a United States taxpayer
identification number. A look-through rule would apply in the case of tiered
partnerships. The Proposed Regulations are proposed to be effective for payments
made after December 31, 1997. There can be no assurance that the Proposed
Regulations will be adopted or as to the provisions that they will include if
and when adopted in temporary or final form.
 
BACKUP WITHHOLDING AND INFORMATION REPORTING
 
UNITED STATES HOLDERS
 
    In general, information reporting requirements will apply to payments of
principal, any premium and interest on a Note and the proceeds of the sale of a
Note before maturity within the United States to, and to the accrual of OID on a
Discount Note with respect to, non-corporate United States Holders, and "backup
withholding" at a rate of 31% will apply to such payments and to payments of OID
if the United States Holder fails to provide an accurate taxpayer identification
number or is notified by the Service that it has failed to report all interest
and dividends required to be shown on its federal income tax returns.
 
UNITED STATES ALIEN HOLDERS
 
    Under current law, information reporting on Internal Revenue Service Form
1099 and backup withholding will not apply to payments of principal, premium (if
any) and interest (including OID) made by the Company or a paying agent to a
United States Alien Holder on a Note; provided, the certification described in
clause (i)(c) under "United States Alien Holders" above is received; and
provided further that the payor does not have actual knowledge that the holder
is a United States person. The Company or a paying agent, however, may report
(on Internal Revenue Service Form 1042S) payments of interest (including OID) on
Notes. See the discussion above with respect to the rules under the Proposed
Regulations.
 
    Payments of the proceeds from the sale by a United States Alien Holder of a
Note made to or through a foreign office of a broker will not be subject to
information reporting or backup withholding, except that if the broker is a
United States person, a controlled foreign corporation for United States tax
purposes or a foreign person 50% or more of whose gross income is effectively
connected with a United States trade or business for a specified three-year
period, information reporting may apply to such payments. Payments of the
proceeds from the sale of a Note to or through the United States office of a
broker is subject to information reporting and backup withholding unless the
holder or beneficial owner certifies as to its non-United States status or
otherwise establishes an exemption from information reporting and backup
withholding.
 
                       SUPPLEMENTAL PLAN OF DISTRIBUTION
 
    Subject to the terms set forth in the Distribution Agreement, dated August
15, 1996 (the "Distribution Agreement"), the Notes are being offered on a
continuing basis by the Company through agents, including Goldman, Sachs & Co.
and Morgan Stanley & Co. Incorporated (collectively, the "Agents"). Goldman,
Sachs & Co. and Morgan Stanley & Co. Incorporated have agreed to use reasonable
efforts to solicit purchases of the Notes. The Company will have the sole right
to accept offers to purchase Notes and may reject any proposed purchase of Notes
as a whole or in part. The Agents shall have the right, in their discretion
reasonably exercised, to reject any offer to purchase Notes, as a whole or in
part. The Company will pay the Agents a commission of from .125% to .750% of the
principal amount of Notes, depending upon maturity, for sales made through them
as Agents, with commissions with respect to Notes in excess of 30 years to be
negotiated between the Company and the Agents at the time of sale.
 
                                      S-25

    The Company may also sell Notes to the Agents as principals for their own
accounts at a discount to be agreed upon at the time of sale, or the purchasing
Agents may receive from the Company a commission or discount equivalent to that
set forth on the cover page of this Prospectus Supplement in the case of any
such principal transaction in which no other discount is agreed. Such Notes may
be resold at prevailing market prices, or at prices related thereto, at the time
of such resale, as determined by the Agents. The Company reserves the right to
sell Notes directly on its own behalf. No commission will be payable on any
Notes sold directly by the Company.
 
    In addition, the Agents may offer the Notes they have purchased as principal
to other dealers. The Agents may sell Notes to any dealer at a discount and,
unless otherwise specified in the applicable Pricing Supplement, such discount
allowed to any dealer may include all or part of the discount to be received
from the Company. Unless otherwise indicated in the applicable Pricing
Supplement, any Note sold to an Agent as principal will be purchased by such
Agent at a price equal to 100% of the principal amount thereof less a percentage
equal to the commission applicable to any agency sale of a Note of identical
maturity. After the initial public offering of Notes to be resold to investors
and other purchasers on a fixed public offering price basis, the public offering
price, concession and discount may be changed.
 
    The Agents, as agents or principals, may be deemed to be "underwriters"
within the meaning of the Securities Act of 1933 (the "Act"). The Company has
agreed to indemnify the Agents against certain liabilities, including
liabilities under the Act. The Company has agreed to reimburse the Agents for
certain expenses.
 
    The Agents may sell to or through dealers who may resell to investors, and
the Agents may pay all or part of their discount or commission to such dealers.
Such dealers may be deemed to be "underwriters" within the meaning of the Act.
 
    The Notes are a new issue of securities with no established trading market
and will not be listed on any securities exchange. No assurance can be given as
to the existence or liquidity of the secondary market for the Notes.
 
    Unless otherwise indicated in the applicable Pricing Supplement, payment of
the purchase price of Notes will be required to be made in immediately available
funds in The City of New York.
 
    Certain of the underwriters or agents and their associates may be customers
of, engage in transactions with, and perform services for the Company in the
ordinary course of business.
 
                               VALIDITY OF NOTES
 
    The validity of the Notes will be passed upon for the Company by Kevin J.
Tierney, Senior Vice President, Secretary and General Counsel and Skadden, Arps,
Slate, Meagher & Flom, New York, New York with respect to certain matters of New
York law, and for the Agents by Sullivan & Cromwell, New York, New York. The
opinions of Kevin J. Tierney, Skadden, Arps, Slate, Meagher & Flom and Sullivan
& Cromwell will be based upon, and subject to, certain assumptions as to future
actions required to be taken in connection with the issuance and sale of the
Notes and as to other events that may affect the validity of the Notes but that
cannot be ascertained on the date of such opinions.
 
                                      S-26

                                UNUM CORPORATION
                       DEBT SECURITIES, PREFERRED STOCK,
                           COMMON STOCK AND WARRANTS
                               -----------------
 
    UNUM  Corporation may from  time to time offer,  together or separately, its
(i) debt securities  (the "Debt  Securities") which  may be  either senior  debt
securities  (the "Senior Debt Securities")  or subordinated debt securities (the
"Subordinated Debt Securities"); (ii)  shares of its  preferred stock, $.10  par
value  (the "Preferred Stock"); (iii) shares of its common stock, $.10 par value
(the "Common Stock"); and (iv)  warrants to purchase Debt Securities,  Preferred
Stock, Common Stock or other securities of the Company as shall be designated by
the  Company at the time of offering (the "Warrants"), in amounts, at prices and
on terms  to  be  determined at  the  time  of offering.  The  Debt  Securities,
Preferred   Stock,  Common  Stock  and  Warrants  are  collectively  called  the
"Securities."
 
    The Securities offered pursuant to this  Prospectus may be issued in one  or
more  series or issuances  and will be limited  to $500,000,000 aggregate public
offering price (or its equivalent (based on the applicable exchange rate at  the
time  of sale) in  one or more  foreign currencies, currency  units or composite
currencies as shall be designated by the Company). Certain specific terms of the
particular Securities in respect of which this Prospectus is being delivered are
set  forth   in  the   accompanying  Prospectus   Supplement  (the   "Prospectus
Supplement"),  including, where applicable, (i) in  the case of Debt Securities,
the specific title, aggregate principal amount, whether such Debt Securities are
Senior Debt Securities or Subordinated  Debt Securities, maturity date,  initial
public  offering or purchase price, interest rate  or rates (which may be fixed,
floating or adjustable)  and timing  of payments thereof,  yield, provision  for
redemption  or sinking fund requirements, if  any, currencies of denomination or
currencies otherwise applicable  thereto, terms for  any conversion or  exchange
into Common Stock or other securities or property of the Company, in the case of
Subordinated  Debt  Securities,  any  other variable  terms,  any  listing  on a
securities exchange and methods of distribution;  (ii) in the case of  Preferred
Stock,  the specific  title, the aggregate  amount, any  dividend (including the
method of calculating payment of dividends), liquidation, redemption, voting and
other rights, any  terms for  any conversion or  exchange into  Common Stock  or
other  securities or  property of the  Company, methods of  distribution and the
initial public offering or purchase price and other special terms; (iii) in  the
case  of Common Stock,  the methods of  distribution and the  public offering or
purchase price; and (iv) in the case of Warrants, the securities of the  Company
which  are  issuable upon  exercise of  the Warrants,  the exercise  period, the
methods of distribution, the initial public  offering or purchase price and  the
exercise  price  and  detachability  of  such  Warrants  if  issued  with  other
securities. All or a portion of the Debt Securities of a series may be  issuable
in  temporary or permanent global form. The  Company's Common Stock is listed on
the New York  Stock Exchange and  the Pacific Stock  Exchange under the  trading
symbol  "UNM." Any Common Stock sold pursuant to a Prospectus Supplement will be
listed on such exchanges, subject to official notice of issuance.
 
    The Debt  Securities will  be  unsecured. Unless  otherwise specified  in  a
Prospectus  Supplement, the  Senior Debt Securities  will rank  equally with all
other unsecured and unsubordinated indebtedness of the Company. The Subordinated
Debt Securities  will  be  subordinated  in  right  of  payment  to  all  Senior
Indebtedness of the Company (as hereinafter defined).
 
    The  Prospectus Supplement may contain information concerning certain United
States Federal income  tax considerations applicable  to the Securities  offered
therein.
 
    The  Securities  may be  sold  by the  Company  directly or  through agents,
underwriters  or  dealers,  as  designated  from  time  to  time  or  through  a
combination  of  such  methods. If  agents  of  the Company  or  any  dealers or
underwriters are involved in the sale of the Securities in respect of which this
Prospectus is being delivered, the names of such agents, dealers or underwriters
and any applicable  commissions or  discounts will  be set  forth in  or may  be
calculated  from the Prospectus Supplement with  respect to such Securities. See
"Plan of Distribution."
 
    This Prospectus may  not be used  to consummate sales  of Securities  unless
accompanied by a Prospectus Supplement.
 
 THESE  SECURITIES HAVE NOT BEEN APPROVED  OR DISAPPROVED BY THE SECURITIES AND
 EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
  AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
    ACCURACY OR  ADEQUACY OF  THIS PROSPECTUS.  ANY REPRESENTATION  TO  THE
                        CONTRARY IS A CRIMINAL OFFENSE.
                              -------------------
 
                 THE DATE OF THIS PROSPECTUS IS AUGUST 2, 1996.

    NO  PERSON  HAS BEEN  AUTHORIZED  TO GIVE  ANY  INFORMATION OR  TO  MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED OR INCORPORATED BY REFERENCE IN  THIS
PROSPECTUS  IN CONNECTION  WITH THE OFFER  CONTAINED IN THIS  PROSPECTUS AND, IF
GIVEN OR MADE, SUCH  INFORMATION OR REPRESENTATIONS MUST  NOT BE RELIED UPON  AS
HAVING  BEEN AUTHORIZED BY  THE COMPANY OR ANY  UNDERWRITERS, DEALERS OR AGENTS.
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR SOLICITATION OF AN OFFER
TO BUY SECURITIES IN ANY  JURISDICTION TO ANY PERSON TO  WHOM IT IS UNLAWFUL  TO
MAKE SUCH OFFER OR SOLICITATION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY
SALE  MADE HEREUNDER SHALL, UNDER ANY  CIRCUMSTANCES, CREATE AN IMPLICATION THAT
THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF  OR
THAT  THE INFORMATION CONTAINED HEREIN IS CORRECT  AT ANY TIME SUBSEQUENT TO THE
DATE HEREOF.
 
                                 NORTH CAROLINA
 
    The Commissioner  of  Insurance of  the  State  of North  Carolina  has  not
approved  or disapproved this offering nor  has the commissioner passed upon the
accuracy or adequacy of this Prospectus.
 
                             AVAILABLE INFORMATION
 
    The Company is subject to  the informational requirements of the  Securities
Exchange  Act  of  1934, as  amended  (the  "Exchange Act"),  and  in accordance
therewith files  reports,  proxy  statements  and  other  information  with  the
Securities  and  Exchange  Commission  (the  "Commission").  Reports,  proxy and
information statements  and  other  information  filed by  the  Company  can  be
inspected  and  copied  at the  public  reference facilities  maintained  by the
Commission at Room 1024, 450 Fifth Street, N.W., Washington, D.C. 20549, and  at
the  following  Regional Offices  of  the Commission:  Midwest  Regional Office,
Citicorp  Center,  500  West  Madison  Street,  Suite  1400,  Chicago,  Illinois
60661-2511  and Northeast Regional Office, 7 World Trade Center, 13th Floor, New
York, New York 10048. Copies  of such material can  be obtained from the  Public
Reference  Section of the Commission at 450 Fifth Street, N.W., Washington, D.C.
20549at   prescribed   rates.    The   Commission   maintains    a   Web    site
(http://www.sec.gov) that contains reports, proxy and information statements and
other  information  regarding  registrants  that  file  electronically  with the
Commission. Reports,  proxy and  information  statements and  other  information
concerning  the Company  may also be  inspected at  the offices of  the New York
Stock Exchange, Inc., 20 Broad Street, New York, New York 10005 and the  Pacific
Stock  Exchange,  301 Pine  Street, San  Francisco,  California 94104,  on which
certain of the Company's securities are listed.
 
    The Company has filed with the  Commission a registration statement on  Form
S-3  under the Securities Act  of 1933, as amended  (the "Securities Act"), with
respect to the  Securities offered hereby  (the "Registration Statement").  This
Prospectus does not contain all of the information set forth in the Registration
Statement,  certain parts of which are omitted  in accordance with the rules and
regulations of the Commission. Reference  is made to the Registration  Statement
and to the exhibits relating thereto for further information with respect to the
Company and the Securities offered hereby.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
    The  Company's Annual Report on Form 10-K for the fiscal year ended December
31, 1995 (except for Items 7 and 8 of Part II and Item 14 of Part IV), Quarterly
Report on Form 10-Q for the three-month period ended March 31, 1996, and Current
Report on  Form 8-K  dated January  24, 1996,  filed by  the Company  under  the
Exchange  Act,  and the  description  of the  Company's  Common Stock  and Share
Purchase Rights Plan contained in its Registration Statements filed pursuant  to
Section 12 of the Exchange Act and any amendment or report filed for the purpose
of updating those descriptions, are incorporated herein by reference.
 
    All  documents filed by the Company  with the Commission pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date hereof  and
prior  to the  termination of  the offering  of the  Securities shall  hereby be
deemed to be incorporated  by reference into  this Prospectus and  to be a  part
hereof  from the date of filing of  such documents. Any statement contained in a
document incorporated or deemed to be incorporated by reference herein shall  be
deemed  to be  modified or  superseded for  purposes of  this Prospectus  to the
extent that a  statement contained  herein or  in any  other subsequently  filed
document which also is or is deemed to be incorporated by reference herein or in
the  accompanying Prospectus  Supplement modifies or  supersedes such statement.
Any such statement so modified or superseded  shall not be deemed, except as  so
modified or superseded, to constitute a part of this Prospectus.
 
    The  Company  will  provide  without  charge to  each  person  to  whom this
Prospectus is delivered, on written  or oral request of  such person, a copy  of
any  or  all of  the  foregoing documents  incorporated  by reference  into this
Prospectus (without exhibits to such documents other than exhibits  specifically
incorporated  by reference into such documents). Requests for such copies should
be directed to  the office  of the  Secretary, UNUM  Corporation, 2211  Congress
Street, Portland, Maine, 04122, telephone number (207) 770-4319.
 
                                       2

                                  THE COMPANY
 
    UNUM Corporation ("the Company") is a Delaware corporation organized in 1985
as  an insurance holding company. The  Company and its subsidiaries ("UNUM") are
the leading providers of group long  term disability insurance ("group LTD")  in
the  United States  and the  United Kingdom.  UNUM is  also a  major provider of
employee benefits, individual disability insurance and special risk reinsurance.
UNUM also markets long term care  and retirement income products. UNUM is  based
in  Portland, Maine and through its affiliates has offices in North America, the
United Kingdom and the  Pacific Rim. The  Company's principal executive  offices
are  located at  2211 Congress Street,  Portland, Maine 04122  and its telephone
number is (207) 770-2211.
 
    The operations of the following  subsidiaries account for substantially  all
of  UNUM's  consolidated assets  and revenues:  UNUM  Life Insurance  Company of
America ("UNUM America"), the leading provider of group disability insurance  in
the  nation and a provider  of employee benefits, long  term care and retirement
products; First  UNUM  Life Insurance  Company  (New York  state  only)  ("First
UNUM");  Commercial Life Insurance  Company, a leader  in special risk insurance
and professional  association insurance  marketing;  UNUM Limited,  the  leading
group  disability insurance  provider in the  United Kingdom;  Duncanson & Holt,
Inc., a leading accident and  health reinsurance underwriting manager;  Colonial
Life  & Accident  Insurance Company  ("Colonial"), a  leader in payroll-deducted
voluntary employee benefits offered  to employees at  their worksites; and  UNUM
Japan Accident Insurance Company Limited.
 
BUSINESS SEGMENTS
 
    UNUM   reports  its  operations  principally   in  four  business  segments:
Disability Insurance, Special Risk  Insurance, Colonial Products and  Retirement
Products.  Corporate  includes  transactions  that  are  generally non-insurance
related and interest expense on corporate borrowings.
 
    DISABILITY INSURANCE SEGMENT.   The Disability  Insurance segment, which  in
1995  accounted for  60.0% of  UNUM's revenues  and 56.8%  of its  income before
income taxes, includes disability products offered in North America, the  United
Kingdom  and Japan including: group LTD, individual disability, group short term
disability, association group disability,  disability reinsurance and long  term
care insurance.
 
    Group  LTD  is the  Disability Insurance  segment's principal  product. UNUM
America and First UNUM  target sales of group  LTD to executive,  administrative
and  management personnel, and other professionals. Since 1976, UNUM America and
First UNUM combined have been the  United States' leading provider of group  LTD
according  to EMPLOYEE BENEFIT  PLAN REVIEW, a  recognized industry publication.
UNUM  Limited  targets   group  LTD   sales  to   management  personnel,   other
professionals,  and technical and skilled artisans. UNUM Limited was the leading
provider for 1995 of group LTD insurance  in the United Kingdom, as reported  by
Employers Re. International.
 
    SPECIAL  RISK INSURANCE SEGMENT.  The Special Risk Insurance segment in 1995
accounted for 18.2%  of UNUM's revenues  and 15.8% of  its income before  income
taxes.  The Special  Risk Insurance  segment includes  group life,  special risk
accident   insurance,   non-disability   reinsurance   operations,   reinsurance
underwriting management operations and other special risk insurance products.
 
    COLONIAL  PRODUCTS SEGMENT.  The Colonial Products segment in 1995 accounted
for 12.8% of UNUM's revenues  and 23.0% of its  income before income taxes.  The
Colonial  Products  segment  includes  Colonial  and  affiliates.  Colonial, the
principal subsidiary,  markets  a  broad  line  of  payroll-deducted,  voluntary
benefits  to  employees  at  their worksites,  while  focusing  on  accident and
sickness, cancer and life products.
 
    RETIREMENT PRODUCTS SEGMENT.  The Retirement Products segment accounted  for
8.7%  of UNUM's revenues  and 11.9% of  its income before  income taxes in 1995.
This segment markets and services tax-
 
                                       3

sheltered annuities in UNUM America and  First UNUM. This segment also  includes
guaranteed  investment contracts, deposit administration accounts, 401(k) plans,
individual life and group medical insurance, all of which are no longer actively
marketed by UNUM.
 
RECENT DEVELOPMENTS
 
    During the first quarter of 1996,  UNUM America and First UNUM entered  into
an  agreement  for  the sale  of  their respective  group  tax-sheltered annuity
("TSA") businesses  to The  Lincoln National  Life Insurance  Company  ("Lincoln
Life"),  a part of Lincoln National Corporation, and to a new New York insurance
subsidiary of Lincoln Life. The sale, which is subject to regulatory  approvals,
involves  approximately 1,700 group contractholders  and assets under management
of  approximately  $3   billion.  The  agreement   initially  contemplates   the
reinsurance of these contracts under an indemnity reinsurance arrangement. These
contracts   will  then  be  reinsured  pursuant  to  an  assumption  reinsurance
arrangement upon consent  of the  TSA contractholders  and/or participants.  The
purchase  price (ceding commission)  at closing is  expected to be approximately
$70 million. It is anticipated  that it will take  several months to obtain  the
necessary approvals and otherwise close the sale. There is no guarantee that the
sale will close.
 
    On February 7, 1996, UNUM announced plans to merge Commercial Life Insurance
Company  into UNUM  America to accelerate  growth of its  special risk business,
increase its  commitment  to  the  association group  business  and  to  improve
operating  and capital efficiencies. The merger  is expected to become effective
on December 31, 1996, subject to regulatory approvals.
 
    On December 29, 1993,  UNUM filed suit in  the United States District  Court
for  the District  of Maine, seeking  a federal  income tax refund.  The suit is
based on a claim for a deduction in certain prior tax years, for $652 million in
cash and  stock  distributed  to  policyholders  in  connection  with  the  1986
conversion  of Union Mutual Life Insurance Company  to a stock company. UNUM has
fully paid, and provided  for in prior years'  financial statements, the tax  at
issue  in  this litigation.  On  May 23,  1996,  the District  Court  issued its
decision that the  distribution in  question was not  a deductible  expenditure.
UNUM  believes its claims are meritorious, and expects to appeal the decision to
the Court  of Appeals  for the  First Circuit.  The ultimate  recovery, if  any,
cannot be determined at this time.
 
INVESTMENTS
 


                                                                  DECEMBER 31, 1995        DECEMBER 31, 1994
                                                               -----------------------  -----------------------
                                                                CARRYING       FAIR      CARRYING       FAIR
                                                                 AMOUNT       VALUE       AMOUNT       VALUE
                                                               -----------  ----------  -----------  ----------
                                                                            (DOLLARS IN MILLIONS)
                                                                                         
Fixed maturities:
  Available for sale.........................................  $   9,135.4  $  9,135.4  $   1,640.6  $  1,640.6
  Held to maturity...........................................           --          --      6,227.2     6,168.6
Equity securities available for sale.........................         25.2        25.2        627.9       627.9
Mortgage loans...............................................      1,163.4     1,274.9      1,216.3     1,265.4
Real estate..................................................        222.2                    190.8
Policy loans.................................................        219.2       219.2        201.0       201.0
Other long-term investments..................................         30.4                     38.1
Short-term investments.......................................        896.7       896.7        291.9       291.9
                                                               -----------              -----------
      Total investments......................................  $  11,692.5              $  10,433.8
                                                               -----------              -----------
                                                               -----------              -----------

 
    UNUM's  investment portfolio is concentrated in investment grade bonds. UNUM
evaluates total expected return after  consideration of associated expenses  and
losses,  within  criteria  established  for  each  product  line.  Product  line
investment strategies are developed to complement business risks by meeting  the
liquidity  and solvency requirements of each product. UNUM purchases assets with
maturities, expected cash  flows and prepayment  conditions that are  consistent
with these strategies. The
 
                                       4

nature  and quality of the types of investments comply with policies established
by  management,  which  are  more  stringent  overall  than  the  statutes   and
regulations  imposed by the jurisdictions in which UNUM's insurance subsidiaries
are licensed.  UNUM's investments  are reported  in the  consolidated  financial
statements  at  net realizable  value or  net of  any applicable  allowances for
probable losses.
 
    During the second  quarter of 1995,  UNUM sold virtually  all of the  common
stock   portfolio  of   its  United   States  subsidiaries,   primarily  due  to
consideration of statutory  capital requirements associated  with investment  in
common  stocks and to increase future investment income. UNUM has reinvested the
proceeds from the  sale of the  common stock portfolio  primarily in  investment
grade  fixed  income  assets.  Dependent on  capital  considerations  and market
conditions, UNUM may invest in equity securities in the future.
 
    In November 1995, the  FASB issued "A Guide  to Implementation of  Statement
115  on Accounting for Certain Investments in Debt and Equity Securities," which
provided  a  one-time  opportunity  to  reassess  the  appropriateness  of   the
classifications  of securities  described in  FAS 115,  and to  reclassify fixed
maturities from the held to maturity category without calling into question  the
intent  to hold other debt securities to maturity in the future. On December 31,
1995, UNUM reassessed  its fixed maturity  portfolio and, as  allowed under  the
implementation guidance, reclassified fixed maturities with an amortized cost of
$6,082.8  million and a related  net unrealized gain of  $393.0 million from the
held to maturity category to available for sale.
 
    At December 31, 1995, the  fixed maturity portfolio included $139.4  million
of  below investment  grade bonds  (below "Baa")  recorded at  fair value, which
represented 1.5%  of  the  fixed  maturity  portfolio,  and  had  an  associated
amortized  cost of $133.8 million.  At December 31, 1994,  the carrying value of
below investment grade bonds included in the fixed maturity portfolio was $193.8
million, which represented  2.5% of  the fixed  maturity portfolio,  and had  an
associated  market value  of $193.4  million. The  percentage of  mortgage loans
delinquent 60 days or more on a contract delinquency basis was 0.2% and 1.8%  at
December 31, 1995, and 1994, respectively.
 
                                       5

              SELECTED CONSOLIDATED FINANCIAL DATA OF THE COMPANY
 


                                                                                 YEAR ENDED DECEMBER 31,
                                                              -------------------------------------------------------------
                                                                 1995        1994        1993           1992        1991
                                                              ----------  ----------  ----------     ----------  ----------
                                                                      (DOLLARS IN MILLIONS, EXCEPT PER SHARE DATA)
                                                                                                  
INCOME STATEMENT DATA
Revenues
  Premiums..................................................  $  3,018.2  $  2,721.3  $  2,474.1     $  2,142.4  $  1,938.9
  Net investment income (a).................................     1,031.4       815.8       839.8          850.7       811.6
  Fees and other income.....................................        73.3        75.5        83.1           55.4        34.0
                                                              ----------  ----------  ----------     ----------  ----------
Total revenues..............................................     4,122.9     3,612.6     3,397.0        3,048.5     2,784.5
Benefits and expenses
  Benefits to policyholders.................................     2,493.0     2,239.0     1,775.7        1,532.6     1,387.1
  Interest credited.........................................       227.4       242.7       281.0          328.4       357.7
  Operating expenses........................................       728.2       713.0       675.6          590.9       554.8
  Commissions...............................................       369.9       355.9       326.8          298.9       258.8
  Increase in deferred policy acquisition costs.............      (114.7)     (155.3)     (135.1)        (111.7)     (104.8)
  Interest expense..........................................        37.2        18.7        12.7           10.9        11.3
                                                              ----------  ----------  ----------     ----------  ----------
    Total benefits and expenses.............................     3,741.0     3,414.0     2,936.7        2,650.0     2,464.9
                                                              ----------  ----------  ----------     ----------  ----------
Income before income taxes and cumulative effects of
 accounting changes.........................................       381.9       198.6       460.3          398.5       319.6
Income taxes................................................       100.8        43.9       148.3          107.3        74.3
                                                              ----------  ----------  ----------     ----------  ----------
Income before cumulative effects of accounting changes......       281.1       154.7       312.0          291.2       245.3
Cumulative effects of accounting changes....................          --          --       (12.1)            --          --
                                                              ----------  ----------  ----------     ----------  ----------
    Net Income..............................................  $    281.1  $    154.7  $    299.9     $    291.2  $    245.3
                                                              ----------  ----------  ----------     ----------  ----------
                                                              ----------  ----------  ----------     ----------  ----------
BALANCE SHEET DATA
(at end of period)
Assets......................................................  $ 14,787.8  $ 13,127.2  $ 12,437.3     $ 11,959.8  $ 11,310.9
Short-term debt.............................................  $    126.5  $    246.6  $    110.0     $    122.7  $    150.1
Long-term debt..............................................  $    457.3  $    182.1  $    128.6     $     77.2  $     51.5
Stockholders' equity........................................  $  2,302.9  $  1,915.4  $  2,102.7     $  2,010.9  $  1,755.5
 
OTHER DATA
Earnings per share..........................................  $     3.87  $     2.09  $     3.81(b)  $     3.71  $     3.15
Dividends paid per share....................................  $    1.035  $     0.92  $    0.765     $    0.625  $     0.49
Book value per share........................................  $    31.54  $    26.45  $    27.67     $    25.44  $    22.46
Number of shares (millions):
  Shares outstanding........................................        73.0        72.4        76.0           79.1        78.2
  Weighted average shares outstanding.......................        72.7        74.2        78.8           78.5        77.8
Ratio of earnings to fixed charges (c)......................         9.0         7.7        20.0           19.1        14.0

 
- ----------
(a)  Net investment income  is comprised of investment  income (net of expenses)
    and net realized investment gains.
(b) Earnings  per share  before  cumulative effects  of accounting  changes  was
    $3.96.  Effective January 1, 1993,  the Company adopted Financial Accounting
    Standard No. 106, "Employers'  Accounting for Postretirement Benefits  Other
    than  Pensions," which decreased  net income by $32.1  million, or $0.40 per
    share, and Financial  Accounting Standard  No. 109,  "Accounting for  Income
    Taxes," which increased net income by $20.0 million, or $0.25 per share.
(c)  For purposes of computing the ratio  of earnings to fixed charges, earnings
    as adjusted consist of income from continuing operations before income taxes
    plus fixed  charges.  Fixed charges  consist  of interest  expense  and  the
    estimated interest portion of rent expense.
 
                                       6

       SELECTED CONSOLIDATED SEGMENT INCOME STATEMENT DATA OF THE COMPANY
 


                                                                            YEAR ENDED DECEMBER 31,
                                                              ---------------------------------------------------
                                                                1995      1994      1993         1992      1991
                                                              --------  --------  --------     --------  --------
                                                                             (DOLLARS IN MILLIONS)
                                                                                          
Premiums and other income:
  Disability Insurance Segment..............................  $1,879.9  $1,716.2  $1,547.9     $1,339.8  $1,214.6
  Special Risk Insurance Segment............................     702.3     607.1     559.4        432.8     368.5
  Colonial Products Segment.................................     475.1     441.3     407.4        371.9     325.4
  Retirement Products Segment                                     34.1      31.4      42.5         52.5      64.4
  Corporate.................................................       0.1       0.8        --          0.8        --
                                                              --------  --------  --------     --------  --------
    Total premiums and other income.........................   3,091.5   2,796.8   2,557.2      2,197.8   1,972.9
                                                              --------  --------  --------     --------  --------
Net investment income: (a)
  Disability Insurance Segment..............................     592.9     400.3     369.8        370.5     333.8
  Special Risk Insurance Segment............................      48.4      40.7      34.8         32.2      26.5
  Colonial Products Segment.................................      52.2      32.6      41.4         35.4      38.5
  Retirement Products Segment...............................     323.7     338.0     387.6        408.7     411.3
  Corporate.................................................      14.2       4.2       6.2          3.9       1.5
                                                              --------  --------  --------     --------  --------
    Total net investment income.............................   1,031.4     815.8     839.8        850.7     811.6
                                                              --------  --------  --------     --------  --------
    Total revenues..........................................   4,122.9   3,612.6   3,397.0      3,048.5   2,784.5
                                                              --------  --------  --------     --------  --------
Benefits and expenses:
  Disability Insurance Segment..............................   2,255.8   2,060.3   1,603.6      1,446.6   1,306.4
  Special Risk Insurance Segment............................     690.4     581.9     555.3        418.7     355.2
  Colonial Products Segment.................................     439.6     411.2     378.4        346.8     306.4
  Retirement Products Segment                                    312.3     327.4     375.8        427.5     484.4
  Corporate.................................................      42.9      33.2      23.6         10.4      12.5
                                                              --------  --------  --------     --------  --------
    Total benefits and expenses.............................   3,741.0   3,414.0   2,936.7      2,650.0   2,464.9
                                                              --------  --------  --------     --------  --------
Income (loss) before income taxes and cumulative effects of
 accounting changes:
  Disability Insurance Segment..............................     217.0      56.2     314.1        263.7     242.0
  Special Risk Insurance Segment............................      60.3      65.9      38.9         46.3      39.8
  Colonial Products Segment.................................      87.7      62.7      70.4         60.5      57.5
  Retirement Products Segment...............................      45.5      42.0      54.3         33.7      (8.7)
  Corporate.................................................     (28.6)    (28.2)    (17.4)        (5.7)    (11.0)
                                                              --------  --------  --------     --------  --------
    Total income before income taxes and cumulative effects
     of accounting changes..................................     381.9     198.6     460.3        398.5     319.6
                                                              --------  --------  --------     --------  --------
Income taxes................................................     100.8      43.9     148.3        107.3      74.3
                                                              --------  --------  --------     --------  --------
Cumulative effects of accounting changes....................        --        --     (12.1)(b)       --        --
                                                              --------  --------  --------     --------  --------
    Net income..............................................  $  281.1  $  154.7  $  299.9     $  291.2  $  245.3
                                                              --------  --------  --------     --------  --------
                                                              --------  --------  --------     --------  --------

 
- ----------
(a)  Net investment income  is comprised of investment  income (net of expenses)
    and net realized investment gains.
 
(b) Effective January 1, 1993, the Company adopted Financial Accounting Standard
    No. 106,  "Employers'  Accounting  for Postretirement  Benefits  Other  than
    Pensions,"  which decreased net income by $32.1 million, or $0.40 per share,
    and Financial Accounting  Standard No. 109,  "Accounting for Income  Taxes,"
    which increased net income by $20.0 million, or $0.25 per share.
 
                                       7

                                USE OF PROCEEDS
 
    Except  as set forth in a Prospectus  Supplement, the Company intends to use
the net proceeds from the sale of the Securities for general corporate purposes,
including working  capital, capital  expenditures, investment  in  subsidiaries,
refinancing   of  debt,  possible  future  business  acquisitions  and  for  the
repurchase of its Common Stock. The Company does not have any present plans, and
is not engaged in  any negotiations, for  the use of any  such proceeds, or  the
issuance  of  Common  Stock, in  any  future  acquisition. Any  proposal  to use
proceeds from any offering of Securities in connection with an acquisition  will
be disclosed in the Prospectus Supplement relating to such offering.
 
                         DESCRIPTION OF DEBT SECURITIES
 
    The following description sets forth certain general terms and provisions of
the  Debt  Securities  to  which  any  Prospectus  Supplement  may  relate.  The
particular terms of the Debt Securities offered by any Prospectus Supplement and
the extent, if any, to which such  general provisions may not apply to the  Debt
Securities so offered will be described in the Prospectus Supplement relating to
such Debt Securities.
 
    The  Senior Debt Securities are to be issued under an Indenture, dated as of
September 15,  1990  (the "Senior  Indenture"),  between UNUM  Corporation  (for
purposes   of  this   "Description  of   Debt  Securities,"   exclusive  of  its
subsidiaries, the "Company") and The Chase Manhattan Bank, N.A., as trustee. The
Subordinated Debt Securities are to be  issued under a separate Indenture  dated
as  of May 1, 1995 (the "Subordinated Indenture") between the Company and Mellon
Bank, N.A., as trustee. The Senior Indenture and the Subordinated Indenture  are
sometimes  referred to  collectively as the  "Indentures." Copies  of the Senior
Indenture and the Subordinated Indenture are filed or incorporated by  reference
as  exhibits to the Registration  Statement of which this  Prospectus is a part.
The Chase Manhattan Bank, N.A. and Mellon Bank, N.A. are hereinafter referred to
as the "Trustee." The  following summaries of certain  provisions of the  Senior
Debt  Securities, the  Subordinated Debt  Securities and  the Indentures  do not
purport to be complete and are subject  to, and are qualified in their  entirety
by reference to, all the provisions of the Indentures applicable to a particular
series  of Debt Securities, including the  definitions therein of certain terms.
Wherever particular Sections, Articles  or defined terms  of the Indentures  are
referred to, such Sections, Articles or defined terms are incorporated herein by
reference.  Article and  Section references  used herein  are references  to the
applicable Indenture. Except  as otherwise  indicated, the terms  of the  Senior
Indenture  and the Subordinated  Indenture are identical.  Capitalized terms not
otherwise defined herein shall have the meaning given in the Indentures.
 
GENERAL
 
    The  Indentures  do  not  limit  the  aggregate  principal  amount  of  Debt
Securities  which may be issued thereunder and each Indenture provides that Debt
Securities may be issued thereunder from time to time in one or more series. The
Debt Securities will be unsecured. Unless otherwise specified in the  Prospectus
Supplement,  the  Senior  Debt  Securities when  issued  will  be unsubordinated
obligations of the  Company and  will rank equally  and ratably  with all  other
unsecured  and unsubordinated indebtedness of the Company. The Subordinated Debt
Securities when issued  will be subordinated  in right of  payment to the  prior
payment in full of all Senior Indebtedness (as defined below) of the Company, as
described  under  "Subordination of  Subordinated  Debt Securities"  and  in the
Prospectus Supplement applicable to an offering of Subordinated Debt Securities.
Since the Company is a holding company, the right of the Company, and hence  the
right of creditors of the Company (including the Holders of Debt Securities), to
participate  in  any  distribution of  the  assets  of any  subsidiary  upon its
liquidation or reorganization or otherwise  is necessarily subject to the  prior
claims  of creditors of the subsidiary, except  to the extent that claims of the
Company itself as a creditor of the subsidiary may be recognized.
 
    Reference is made to  the Prospectus Supplement  relating to the  particular
Debt Securities offered thereby (the "Offered Debt Securities") which sets forth
whether the Offered Debt Securities shall be
 
                                       8

Senior  Debt Securities or Subordinated Debt  Securities, and further sets forth
the following terms, where applicable, of  the Offered Debt Securities: (1)  the
title of the Offered Debt Securities; (2) any limit on their aggregate principal
amount;  (3) whether they  are to be  issuable in temporary  or permanent global
form; (4) the  price(s) (expressed as  a percentage of  the aggregate  principal
amount thereof) at which they will be issued; (5) the date(s) on which they will
mature;  (6) the rate(s) (which  may be fixed, floating  or adjustable) at which
they will bear  interest, if any,  and the  date from which  such interest  will
accrue;  (7) the dates  on which such  interest will be  payable and the Regular
Record Dates for  such Interest  Payment Dates;  (8) any  mandatory or  optional
sinking fund or analogous provisions; (9) any index or formula used to determine
the  amount of payments of principal of  and premium, if any, and interest; (10)
the date, if any, after which and  the price(s) at which the Company may  redeem
them  at  its  option;  (11) the  currency  or  currencies  (including composite
currencies) of payment of principal of and premium, if any, and interest thereon
if other  than U.S.  dollars  (the "Specified  Currency");  (12) the  terms  and
conditions,  if  any, pursuant  to which  the  Subordinated Debt  Securities are
convertible into  or  exchangeable  for  Common Stock  or  other  securities  or
property  of the Company;  (13) the Person  to whom any  interest on the Offered
Debt Securities will be  payable, if other  than the Person  in whose name  such
Offered  Debt Securities  are registered  on any  Regular Record  Date; (14) the
place or places where principal of (and  premium, if any) and interest, if  any,
on  Offered Debt Securities will be payable; (15) if other than denominations of
$1,000 and any integral multiple thereof, the denominations in which the Offered
Debt Securities will be issuable; (16) any event or events of default applicable
with respect to the Offered Debt Securities in addition to those provided in the
applicable Indenture;  (17) any  other  covenant or  warranty included  for  the
benefit  of the  Offered Debt  Securities in  addition to  (and not inconsistent
with) those  included  in the  applicable  Indenture  for the  benefit  of  Debt
Securities  of all series,  or any other  covenant or warranty  included for the
benefit of  the Offered  Debt Securities  in lieu  of any  covenant or  warranty
included  in the Indentures for the benefit  of Debt Securities of all series or
any provision that any covenant or warranty included in the applicable Indenture
for the benefit of Debt Securities of all series shall not be for the benefit of
the Offered Debt Securities, or any combination of such covenants, warranties or
provisions; and (18) any other terms. (Section 301) Debt Securities may also  be
issued  under the Indentures upon the  exercise of Warrants. See "Description of
Warrants."
 
    The Indentures do not contain any provisions that afford Holders of the Debt
Securities protection in the event of a highly leveraged or similar  transaction
involving the Company.
 
    Offered  Debt Securities  may be issued  at a substantial  discount to their
principal amount  (the "Original  Issue  Discount Securities").  Certain  United
States  Federal income tax and other considerations applicable to Original Issue
Discount Securities,  and to  Offered Debt  Securities that  are denominated  in
other  than  U.S.  dollars,  will  be  described  in  the  applicable Prospectus
Supplement.
 
    The Indentures provide  the Company  with the  ability, in  addition to  the
ability to issue Offered Debt Securities with terms different from those of Debt
Securities  previously issued, to "reopen" a previous  issue of a series of Debt
Securities and issue additional Offered Debt Securities of such series. (Section
301)
 
DENOMINATIONS, REGISTRATION AND TRANSFER
 
    Unless otherwise  provided  in  an  applicable  Prospectus  Supplement  with
respect  to  a  series  of  Offered  Debt  Securities,  Offered  Debt Securities
denominated in U.S. dollars  will be issued only  in denominations of $1,000  or
any  integral  multiple  thereof  without  coupons.  The  Prospectus  Supplement
relating to a  series of  Offered Debt Securities  denominated in  a foreign  or
composite currency will specify the denominations thereof. (Section 302) Offered
Debt  Securities  of any  series  will be  exchangeable  for other  Offered Debt
Securities of the same series containing identical terms and provisions and of a
like aggregate principal amount and containing identical terms and provisions of
different authorized denominations. (Section 305) Offered Debt Securities may be
issuable under the Indentures  in temporary or  permanent global form.  (Section
202) See "Global Securities."
 
                                       9

    Unless  otherwise  indicated  in an  applicable  Prospectus  Supplement, the
principal office of the Trustee  in The City of New  York will be designated  as
the  Company's Paying  Agent for payments  with respect to  Debt Securities. Any
other Paying Agents in the United States initially designated by the Company for
the Offered Debt Securities will be named in the related Prospectus  Supplement.
The  Company may at any  time designate additional Paying  Agents or rescind the
designation of any Paying Agents or approve a change in the office through which
any Paying Agent acts, except  that the Company will  be required to maintain  a
Paying  Agent in each Place  of Payment for such series.  All monies paid by the
Company to a Paying Agent for the  payment of principal of and premium, if  any,
and interest, if any, on any Debt Security which remains unclaimed at the end of
two  years after such principal,  premium or interest shall  have become due and
payable will be  repaid to  the Company,  and the  Holder of  such Offered  Debt
Security  will thereafter look only to the Company for payment thereof. (Section
1003)
 
GLOBAL SECURITIES
 
    If any Offered Debt Securities are issuable in temporary or permanent global
form, the applicable Prospectus Supplement  will describe the circumstances,  if
any,  under which  beneficial owners of  interests in any  such permanent global
Debt Security may exchange such interests for definitive Offered Debt Securities
of such series and of like tenor and principal amount in any authorized form and
denomination. Principal of and  any premium and interest  on a permanent  global
Debt  Security  will  be  payable  in the  manner  described  in  the applicable
Prospectus Supplement.
 
CERTAIN COVENANTS IN THE INDENTURES
 
    LIMITATIONS ON SALES OF RESTRICTED SUBSIDIARIES' CAPITAL STOCK.  The Company
will not sell, transfer or otherwise dispose of any shares of capital stock of a
Restricted Subsidiary  (other  than directors'  qualifying  shares or  sales  to
Restricted  Subsidiaries), and it  will not permit  any Restricted Subsidiary to
sell, transfer or otherwise dispose of any shares of capital stock of any  other
Restricted  Subsidiary (other than for directors'  qualifying shares or sales or
other transfers to the Company or to a Restricted Subsidiary), unless the entire
capital stock of such Restricted Subsidiary at the time owned by the Company and
its Restricted  Subsidiaries  shall  be disposed  of  at  the same  time  for  a
consideration consisting of cash or other property, which, in the opinion of the
Board  of Directors of the Company, is at least equal to the fair value thereof.
(Section 1006)
 
    For purposes of the Indentures,  "Restricted Subsidiary" means each of  UNUM
Life  Insurance  Company  of America,  First  UNUM Life  Insurance  Company, and
Colonial Companies, Inc., as well as any successor to all or a principal part of
the business of any such subsidiary, any subsidiary which owns or holds  capital
stock  of any such subsidiary and any other subsidiary which the Company's Board
of Directors designates as a Restricted Subsidiary. (Section 101) The Restricted
Subsidiaries accounted for approximately 90% of the consolidated revenues of the
Company during 1995  and approximately  91% of  the consolidated  assets of  the
Company at December 31, 1995.
 
LIMITATIONS ON LIENS ON RESTRICTED SUBSIDIARIES' CAPITAL STOCK.
 
    The  Company will not, and  it will not permit  any Restricted Subsidiary at
any time directly or  indirectly to, create, assume,  incur, or permit to  exist
any  indebtedness secured by a pledge, lien, or other encumbrance on the capital
stock of any  Restricted Subsidiary without  making effective provision  whereby
the  Debt Securities then outstanding (and, if  the Company so elects, any other
indebtedness ranking on a parity with the Debt Securities) shall be equally  and
ratably   secured  with  such  secured  indebtedness   so  long  as  such  other
indebtedness shall be secured. (Section 1007)
 
CONVERSION RIGHTS
 
    The  terms  on  which  Subordinated  Debt  Securities  of  any  series   are
convertible  into  or  exchangeable  for Common  Stock  or  other  securities or
property of the Company will be set forth in the Prospectus Supplement  relating
thereto.  Such  terms  shall  include provisions  as  to  whether  conversion or
exchange is mandatory,  at the  option of  the Holder or  at the  option of  the
Company, and may include provisions
 
                                       10

pursuant  to which the number  of shares of Common  Stock or other securities of
the Company to be received by the Holders of Subordinated Debt Securities  would
be  calculated according to the market price of Common Stock or other securities
of the Company as of a time stated in the Prospectus Supplement. The  conversion
price of any Subordinated Debt Securities of any series that is convertible into
Common  Stock of  the Company  may be  adjusted for  any stock  dividends, stock
splits, reclassification, combinations or similar transactions, as set forth  in
the applicable Prospectus Supplement. (Article Fourteen).
 
SUBORDINATION OF SUBORDINATED DEBT SECURITIES
 
    Unless  otherwise  indicated  in the  Prospectus  Supplement,  the following
provisions will apply to the Subordinated Debt Securities.
 
    The Subordinated  Debt Securities  will,  to the  extent  set forth  in  the
Subordinated  Indenture, be subordinate in right of payment to the prior payment
in full of all Senior Indebtedness.  Upon any payment or distribution of  assets
to  creditors  upon any  liquidation,  dissolution, winding  up, reorganization,
assignment  for  the  benefit  of  creditors,  marshalling  of  assets  or   any
bankruptcy,  insolvency, debt restructuring or similar proceedings in connection
with any insolvency  or bankruptcy  proceeding of  the Company,  the Holders  of
Senior  Indebtedness  will  first be  entitled  to  receive payment  in  full of
principal of  (and  premium,  if any)  and  interest,  if any,  on  such  Senior
Indebtedness  before the  Holders of  the Subordinated  Debt Securities  will be
entitled to receive or retain  any payment in respect  of the principal of  (and
premium,  if  any) or  interest, if  any, on  the Subordinated  Debt Securities.
(Section 1302)
 
    By reason of such subordination, in the event of liquidation or  insolvency,
creditors  of  the Company  may recover  less, ratably,  than Holders  of Senior
Indebtedness and may recover more, ratably, than the Holders of the Subordinated
Debt Securities.
 
    In the event of  the acceleration of the  maturity of any Subordinated  Debt
Securities,  the Holders of  all Senior Indebtedness outstanding  at the time of
such acceleration  will first  be entitled  to receive  payment in  full of  all
amounts  due thereon before the Holders of the Subordinated Debt Securities will
be entitled to receive any payment upon the principal of (or premium, if any) or
interest, if any, on the Subordinated Debt Securities. (Section 1303)
 
    No payments on  account of principal  (or premium, if  any) or interest,  if
any,  in respect of the Subordinated Debt  Securities may be made if there shall
have occurred and be continuing a default in any payment with respect to  Senior
Indebtedness,  or an  event of default  with respect to  any Senior Indebtedness
resulting in  the acceleration  of  the maturity  thereof,  or if  any  judicial
proceeding shall be pending with respect to any such default. (Section 1304) For
purposes  of the subordination provisions, the payment, issuance and delivery of
cash,  property  or  securities  (other  than  stock  and  certain  subordinated
securities  of the Company) upon conversion of a Subordinated Debt Security will
be deemed to constitute payment on account of the principal of such Subordinated
Debt Security.
 
    The Subordinated  Indenture does  not limit  or prohibit  the incurrence  of
additional Senior Indebtedness, which may include indebtedness that is senior to
the  Subordinated Debt Securities,  but subordinate to  other obligations of the
Company. The Senior  Debt Securities  constitute Senior  Indebtedness under  the
Subordinated Indenture.
 
    "Senior  Indebtedness"  is  defined  to  include  all  amounts  due  on  and
obligations in connection with any of the following, whether outstanding at  the
date  of  execution  of the  Subordinated  Indenture or  thereafter  incurred or
created:
 
    (a)  indebtedness,  obligations   and  other   liabilities  (contingent   or
otherwise) of the Company for money borrowed, or evidenced by bonds, debentures,
notes or similar instruments;
 
                                       11

    (b)   reimbursement  obligations   and  other   liabilities  (contingent  or
otherwise)  of  the  Company  with  respect  to  letters  of  credit,   bankers'
acceptances  issued for the account  of the Company or  with respect to interest
rate protection agreements or currency exchange or purchase agreements;
 
    (c) obligations  and liabilities  (contingent or  otherwise) in  respect  of
leases  by the  Company as lessee  which, in conformity  with generally accepted
accounting principles, are accounted for as capitalized lease obligations on the
balance sheet of the Company;
 
    (d) all direct or indirect guarantees  or similar agreements in respect  of,
and  obligations  or  liabilities  (contingent  or  otherwise)  to  purchase  or
otherwise acquire or otherwise to assure a creditor against loss of the  Company
in  respect  of,  indebtedness,  obligations or  liabilities  of  another Person
described in clauses (a) through (c);
 
    (e) any indebtedness  described in clauses  (a) through (d)  secured by  any
mortgage,  pledge, lien or other encumbrance existing on property which is owned
or held by the Company, regardless  of whether the indebtedness secured  thereby
shall have been assumed by the Company; and
 
    (f)  any  and  all deferrals,  renewals,  extensions and  refundings  of, or
amendments, modifications  or supplements  to, any  indebtedness, obligation  or
liability  of the kind described in clauses  (a) through (e); unless in any case
in  the  instrument  creating  or  evidencing  such  indebtedness,   obligation,
liability,  guaranty, assumption, deferral, renewal,  extension or refunding, it
is provided that such indebtedness, obligation, liability, guaranty, assumption,
deferral, renewal, extension  or refunding involved  is not senior  in right  of
payment  to the Subordinated  Debt Securities or that  such indebtedness is PARI
PASSU with or junior to the Subordinated Debt Securities. (Section 101)
 
    The Prospectus  Supplement  may further  describe  the provisions,  if  any,
applicable  to  the  subordination  of the  Subordinated  Debt  Securities  of a
particular series.
 
CONSOLIDATION, MERGER AND SALE OF ASSETS
 
    The Company,  without  the  consent  of  any  Holders  of  Outstanding  Debt
Securities,  may consolidate or  merge with or  into any Person,  or transfer or
lease its assets substantially as an entirety  to any Person, or may acquire  or
lease  the assets of any Person, provided that: (a) the successor formed by such
consolidation or into which  the Company is merged  or which acquires or  leases
the  assets of the Company  substantially as an entirety  is organized under the
laws of any United States jurisdiction and assumes the Company's obligations  on
the  Debt Securities and under the applicable Indenture; (b) after giving effect
to the transaction, no  Event of Default  (and no event  which, after notice  or
lapse of time or both, would become an Event of Default) shall have happened and
be continuing; and (c) certain other conditions are met. (Article Eight)
 
EVENTS OF DEFAULT
 
    Under  the Indentures, the following will  be Events of Default with respect
to Debt  Securities of  a particular  series: (a)  the Company  defaults in  the
payment of interest on any Debt Security of that series when due and payable and
the  Default continues for a period of 30  days; (b) the Company defaults in the
payment of any principal of  and premium, if any, on  any Debt Security of  that
series when due and payable at maturity, upon redemption or otherwise, or in the
deposit  of any sinking fund payment when due by the terms of a Debt Security of
that series; (c) the Company  fails to comply with or  perform any of its  other
agreements, covenants or warranties in the Debt Securities of that series or the
Indenture in respect of Debt Securities of that series and the Default continues
for  60 days after written  notice as provided in  the applicable Indenture; (d)
there shall be a default by the  Company or any Restricted Subsidiary under  any
(i)  debt for money borrowed (including Debt Securities of any series other than
that series), (ii) mortgage, indenture or other instrument under which there may
be issued or may  be secured or evidenced  any indebtedness for money  borrowed,
(iii)  guarantee of payment for money borrowed  or (iv) debt evidenced by bonds,
debentures, notes or other similar instruments (excluding trade accounts payable
or accrued liabilities arising  in the normal course  of business which are  not
overdue by more
 
                                       12

than  90 days or which are being contested in good faith) and such default shall
result in such indebtedness becoming due prior to its stated maturity; PROVIDED,
HOWEVER, a default shall exist under this  clause (d) only if all such  defaults
relate  to  such indebtedness  or such  guarantees  with an  aggregate principal
amount in excess of $5,000,000, the acceleration of which has not been rescinded
or annulled within 10  days after written notice  as provided in the  applicable
Indenture; (e) certain events of bankruptcy, insolvency or reorganization of the
Company  or  any  Restricted Subsidiary;  and  (f)  any other  Event  of Default
provided with  respect to  Debt Securities  of that  series. (Section  501)  The
applicable  Trustee or the  Holders of at  least 25% in  principal amount of the
Outstanding Debt Securities  of that series  (each series acting  as a  separate
class)  may declare all unpaid principal of and accrued interest (or such lesser
amount as may be provided for in the Debt Securities of that series) on all then
Outstanding Debt Securities of that series to be due and payable immediately  if
an  Event  of  Default  (other than  one  in  (e) above)  with  respect  to Debt
Securities of  such  series  shall  occur  and be  continuing  at  the  time  of
declaration. If an Event of Default as specified in (e) above occurs, all unpaid
principal  and accrued interest (or such lesser amount as may be provided for in
the Debt Securities of that series)  shall IPSO FACTO become and be  immediately
due  and payable without any other declaration or act on the part of the Trustee
or any Holder. (Section 502)
 
    At any time after a declaration  of acceleration has been made with  respect
to  Debt Securities of any series, the Holders of a majority in principal amount
of the Outstanding Debt Securities of that series may rescind any declaration of
acceleration with  respect  to  the  Debt Securities  of  that  series  and  its
consequences,  (a) if  the rescission  would not  conflict with  any judgment or
decree; (b) if all existing Events  of Defaults with respect to Debt  Securities
of  that series  have been  cured or waived  except non-payment  of principal or
interest on Debt Securities of that series that has become due solely because of
the acceleration; and (c) to the extent that payment of such interest is lawful,
interest upon overdue interest at the rate or rates prescribed therefore in such
Debt Securities has been paid. (Section  502) Any Event of Default with  respect
to  Debt Securities of any series may be  waived by the Holders of a majority in
principal amount of the Outstanding Debt Securities of that series, except in  a
case  of failure to pay principal or premium, if any, or interest on, or deposit
of any sinking fund payment  with respect to, any  Debt Security of that  series
for  which payment or deposit had not been  subsequently made or in respect of a
covenant or provision which cannot be modified or amended without the consent of
the Holder of each Outstanding Debt  Security of such series affected.  (Section
504)
 
    If any event which is, or after notice or lapse of time or both would become
an  Event of Default (a "Default") occurs with respect to Debt Securities of any
series and it  is known to  the applicable  Trustee, the Trustee  shall mail  to
Holders  of Debt Securities  of that series  a notice of  Default within 90 days
after it occurs unless  such Default shall have  been cured or waived,  PROVIDED
that  except in  the case of  a Default  in the payment  of the  principal of or
premium, if any,  or interest  on, any  Debt Security of  any series  or in  the
making  of any sinking fund  payment payable with respect  to Debt Securities of
any series, the Trustee may withhold the notice  if and so long as the board  of
directors,  the  executive  committee  or  a  trust  committee  of  directors or
Responsible Officers of the  Trustee in good  faith determines that  withholding
the  notice is in the interests of Holders of Debt Securities of that series and
PROVIDED, FURTHER, that in the case of any Default of the character specified in
clause (c) under  "Events of  Default" with respect  to Debt  Securities of  any
series,  no notice to  Holders shall be given  until at least  30 days after the
occurrence thereof. (Section 602)
 
    Reference is made  to the Prospectus  Supplement relating to  any series  of
Debt  Securities which are Original Issue Discount Securities for the particular
provisions relating  to the  principal amount  of such  Original Issue  Discount
Securities  due upon the occurrence of any Event of Default and the continuation
thereof.
 
    The Holders  of a  majority  in principal  amount  of the  Outstanding  Debt
Securities  of a series may direct the  time, method and place of conducting any
proceeding for any remedy  available to the Trustee  or exercising any trust  or
power  conferred on the Trustee with respect  to Debt Securities of such series,
 
                                       13

PROVIDED that the Trustee may refuse to follow any directions that conflict with
any law or the Indenture, are unduly prejudicial to the rights of other  Holders
of  that series,  or would involve  the Trustee in  personal liability. (Section
505)
 
    In case an Event of Default shall occur and be continuing, the Trustee shall
exercise such of its  rights and powers under  the applicable Indenture and  use
the  same degree of care  and skill in their exercise  as a prudent person would
exercise or  use under  the circumstances  in the  conduct of  his own  affairs.
(Section  601)  Before  proceeding to  exercise  any  right or  power  under the
applicable Indenture  at the  direction of  such Holders,  the Trustee  will  be
entitled  to receive from such Holders  security or indemnity satisfactory to it
against the costs,  expenses and liabilities  which might be  incurred by it  in
complying with any such direction. (Section 603)
 
MODIFICATION AND WAIVER
 
    With  certain exceptions, modification or amendment of the Indentures or the
rights of Holders of the  Debt Securities of any series  may be effected by  the
Company  and the Trustee with the consent of  the Holders of at least 66 2/3% in
principal amount  of the  Outstanding Debt  Securities of  each series  affected
thereby,  PROVIDED  that  no such  modification  or amendment  may,  without the
written consent  of  the  Holder  of each  Outstanding  Debt  Security  affected
thereby,  (a) change the Stated Maturity of the principal of, or any installment
of principal of,  or interest on,  any Debt Security;  (b) reduce the  principal
amount of, or the interest on, any Debt Security or any premium payable upon the
redemption  thereof  or reduce  the  amount of  principal  of an  Original Issue
Discount Security which could be declared due and payable upon an  acceleration;
(c) change the Place of Payment or coin or currency of any payment of principal,
any  premium or interest on any Debt Security; (d) impair the right to institute
suit for the enforcement of any payment on or with respect to any Debt Security;
(e) reduce the percentage in principal amount of the Outstanding Debt Securities
of any  series,  the  consent  of  whose Holders  is  required  to  approve  any
supplemental  indenture,  to waive  compliance  with certain  provisions  of the
applicable Indenture or certain defaults  thereunder and their consequences,  or
to  reduce quorum or voting requirements  applicable to meetings of Holders; (f)
in the  case of  Subordinated Debt  Securities, adversely  change the  right  to
convert  or exchange, including decreasing the conversion rate or increasing the
conversion price of such  Subordinated Debt Securities; (g)  in the case of  the
Subordinated  Indenture, modify the subordination provisions in a manner adverse
to the Holders of any Subordinated Debt Securities; or (h) modify the  foregoing
requirements  in (a) through (g) above, requiring  the consent of each Holder of
each Outstanding  Debt Security  affected  thereby, or  the percentage  of  such
Holders  required to waive past defaults, or the percentage of such Holders that
may rescind an acceleration, except to increase any such percentage, and  except
to  provide that other provisions of the Indentures cannot be modified or waived
without the consent  of the Holder  of each Outstanding  Debt Security  affected
thereby.  (Section 902) Except  with respect to  certain fundamental provisions,
the Holders  of at  least a  majority in  principal amount  of Outstanding  Debt
Securities  of any series may, with respect  to such series, waive past defaults
under the Indentures and waive compliance by the Company with certain provisions
of the Indentures. (Section 513)
 
SATISFACTION AND DISCHARGE OF INDENTURES
 
    The Indentures generally provide that  the Company may terminate certain  of
its obligations under the Debt Securities of any series and under the Indentures
(with  respect to  such series) if  (i) all  the Debt Securities  of such series
previously authenticated and  delivered (other  than lost,  destroyed or  stolen
Debt  Securities that have been replaced or  paid or for whose payment money has
been deposited in trust) have been delivered to the Trustee for cancellation and
the Company  has  paid  all  sums  payable by  it  thereunder,  (ii)  such  Debt
Securities  of such series have matured or will mature within one year or all of
them are  to  be  called  for redemption  within  one  year  under  arrangements
satisfactory  to the Trustee for giving the notice of redemption and the Company
irrevocably deposits  with  the Trustee  money  or U.S.  Government  Obligations
sufficient to pay principal of, premium, if any, and interest on the Outstanding
Debt  Securities of such series that are  due or will become due upon redemption
or maturity, as the case
 
                                       14

may be,  and to  pay all  other  sums payable  by it  thereunder or  (iii)  upon
compliance  with certain conditions specified in  the Indentures, 123 days after
the Company  makes the  deposit with  the Trustee  of money  or U.S.  Government
Obligations  specified  in  clause  (ii).  In such  case,  Holders  of  the Debt
Securities must look to the deposited money for payment. (Section 401)
 
    The Indentures further  provide that if  the Company has  made the  election
provided  by  clause (iii)  above, it  may elect  either (a)  to defease  and be
discharged from any and all obligations  with respect to the Debt Securities  of
such  series, except for the obligations to register the transfer or exchange of
such Debt  Securities, to  replace temporary  or mutilated,  destroyed, lost  or
stolen  Debt Securities, to maintain an office  or agency in respect of the Debt
Securities, and to hold moneys for payment in trust ("legal defeasance") or  (b)
to  be released from its obligations with respect to the Debt Securities of such
series under the covenant  default (except with respect  to the covenant to  pay
principal  and  interest)  and cross-acceleration  provisions  under  "Events of
Default" and  from the  restrictions described  under certain  covenants in  the
Indentures,  including "Limitations on Sales of Restricted Subsidiaries' Capital
Stock" and "Limitations  on Liens  on Restricted  Subsidiaries' Capital  Stock,"
and, in the case of Subordinated Debt Securities, the provisions described under
"Subordination  of Subordinated  Debt Securities" ("covenant  defeasance"). As a
condition to legal defeasance or  covenant defeasance, the Company must  deliver
to  the Trustee an  opinion of counsel  (as specified in  the Indentures) to the
effect that the Holders of the Debt Securities of such series will not recognize
income, gain or loss for United States  Federal income tax purposes as a  result
of  such legal defeasance or  covenant defeasance and will  be subject to United
States Federal income tax  on the same  amounts, in the same  manner and at  the
same  times as  would have been  the case  if such legal  defeasance or covenant
defeasance had not occurred. In the case of legal defeasance under clause (a) or
covenant defeasance under  clause (b) above,  a ruling of  the Internal  Revenue
Service may be delivered in lieu of such opinion. (Section 401)
 
    Under  current United States Federal income  tax law, legal defeasance would
likely be treated as a taxable exchange of such Debt Securities for interests in
the defeasance trust. As  a consequence, a Holder  would recognize gain or  loss
equal  to the difference between the Holder's tax basis for such Debt Securities
and the value of the Holder's  interest in the defeasance trust, and  thereafter
would be required to include in income its share of the income, gain and loss of
the  defeasance trust. Under current Federal income tax law, covenant defeasance
would likely  not be  treated as  a taxable  exchange of  such Debt  Securities.
Purchasers  of  such  Debt Securities  should  consult their  tax  advisors with
respect to the more particular tax consequences to them of such legal defeasance
and covenant defeasance, including the applicability and effect of United States
Federal income and other tax law.
 
    The Company may  exercise its legal  defeasance option with  respect to  the
Debt  Securities  of  such series,  notwithstanding  its prior  exercise  of its
covenant defeasance  option.  If  the Company  exercises  its  legal  defeasance
option,  payment of such  Debt Securities may  not be accelerated  because of an
Event of  Default. If  the  Company exercises  its covenant  defeasance  option,
payment  of such Debt Securities may not  be accelerated because of the covenant
default (except with respect to the covenant to pay principal and interest)  and
cross-acceleration provisions or certain of the covenants, including those noted
under  clause (b) above. However, if such  an acceleration were to occur because
of other defaults, the  realizable value at the  acceleration date of the  money
and  U.S. Government Obligations in the defeasance  trust could be less than the
principal and interest then  due on such Debt  Securities, because the  required
deposit  in the defeasance trust is based  upon scheduled cash flows rather than
market value, which will vary depending  upon interest rates and other  factors.
(Section 401)
 
    The term "U.S. Government Obligations" is defined to mean direct obligations
of  the United  States for  the payment of  which its  full faith  and credit is
pledged, or obligations of a person controlled or supervised by and acting as an
agency or  instrumentality of  the United  States and  the payment  of which  is
unconditionally  guaranteed as a full faith  and credit obligation by the United
States which, in either case,  are not callable or  redeemable at the option  of
the issuer thereof, and shall also include a depositary receipt issued by a bank
(as  defined  in  Section  3(a)(2)  of the  Securities  Act)  as  custodian with
 
                                       15

respect to  any  such U.S.  Government  Obligations  or a  specific  payment  of
principal  of or interest on  any such U.S. Government  Obligations held by such
custodian for the  account of the  holder of such  depositary receipt,  PROVIDED
that  (except as required by  law) such custodian is  not authorized to make any
deduction from the amount payable to the holder of such depositary receipt  from
any  amount  received  by  the  custodian  in  respect  of  the  U.S. Government
Obligations or the  specific payment  of principal of  or interest  on the  U.S.
Government Obligations evidenced by such depositary receipt. (Section 101)
 
CONCERNING THE TRUSTEES
 
    The  Company  maintains  banking  relationships in  the  ordinary  course of
business with The Chase Manhattan Bank, N.A. and Mellon Bank, N.A. In  addition,
Mellon  Bank,  N.A. is  a participant  in the  Company's $500  million revolving
credit facility entered into as of December 13, 1994.
 
                          DESCRIPTION OF CAPITAL STOCK
 
    The following descriptions and the descriptions contained in "Description of
Preferred Stock" and "Description of Common Stock" are summaries, and  reference
is  herein made to the detailed provisions of the following documents, copies of
which are filed  as exhibits to  the Registration Statement:  (i) the  Company's
Certificate  of Incorporation, as amended  (the "Certificate of Incorporation");
(ii) the  Company's By-Laws  (the  "By-Laws"); and  (iii) the  Rights  Agreement
between the Company and First Chicago Trust Company of New York, as Rights Agent
(the  "Rights  Agreement"), pursuant  to  which shares  of  Junior Participating
Preferred Stock, Series A ("Junior Participating Preferred Stock") are issuable.
 
    The authorized capital  stock of  the Company consists  of: (i)  120,000,000
shares of Common Stock, par value $0.10 per share, and (ii) 10,000,000 shares of
Preferred Stock, par value $0.10 per share, of which 1,000,000 are designated as
Junior Participating Preferred Stock.
 
    As  of  March 31,  1996, there  were outstanding:  (a) 73,274,752  shares of
Common Stock (as well as the same number of rights to purchase shares of  Junior
Participating  Preferred  Stock,  pursuant  to  the  Rights  Agreement)  and (b)
employee stock options to  purchase an aggregate of  5,835,464 shares of  Common
Stock.
 
                         DESCRIPTION OF PREFERRED STOCK
 
    The following description sets forth certain general terms and provisions of
the Preferred Stock to which any Prospectus Supplement may relate. Certain other
terms  of  a particular  series  of Preferred  Stock  will be  described  in the
Prospectus Supplement relating to that series. If so indicated in the Prospectus
Supplement, the terms of  any such series  may differ from  the terms set  forth
below.  The description of  certain provisions of the  Preferred Stock set forth
below and in any Prospectus  Supplement does not purport  to be complete and  is
subject  to  and  qualified  in  its  entirety  by  reference  to  the Company's
Certificate of Incorporation and the certificate of designation relating to each
such series  of Preferred  Stock, which  will be  filed with  the Commission  in
connection with the offering of such series of Preferred Stock.
 
GENERAL
 
    Under  the Company's Certificate of Incorporation, the Board of Directors is
authorized to fix and determine the  terms, limitations and relative rights  and
preferences  of any class of preferred stock, including, without limitation, any
voting rights thereof, to divide and issue any of the classes of preferred stock
in series, and to fix  and determine the variations  among series to the  extent
permitted  by  law.  The  Company  has  authorized  1,000,000  shares  of Junior
Participating Preferred Stock for issuance upon
 
                                       16

exercise of certain preferred share  purchase rights associated with each  share
of   outstanding  Common  Stock  as  provided   in  the  Rights  Agreement.  See
"Description of Common Stock--Share Purchase Rights Plan,--Description of Junior
Participating Preferred Stock."
 
    The Preferred Stock  shall have  the dividend,  liquidation, redemption  and
voting  rights  set  forth below  unless  otherwise provided  in  the Prospectus
Supplement relating to a particular series of Preferred Stock. Reference is made
to the Prospectus Supplement relating to a particular series of Preferred  Stock
offered thereby for specific terms including: (1) the designation and the number
of  shares offered; (2) the amount of  liquidation preference per share; (3) the
price at which such Preferred  Stock will be issued;  (4) the dividend rate  (or
method  of calculation), the  dates on which dividends  will be payable, whether
such dividends will be cumulative or noncumulative and, if cumulative, the dates
from which dividends will  commence to cumulate; (5)  any redemption or  sinking
fund  provisions; (6) any conversion or  exchange rights; and (7) any additional
voting, dividend,  liquidation,  redemption,  sinking  fund  and  other  rights,
preferences, privileges, limitations and restrictions.
 
    The Preferred Stock offered hereby will be issued in one or more series. The
holders  of  Preferred  Stock will  have  no  preemptive rights.  Any  shares of
Preferred Stock  sold  hereunder  will  be fully  paid  and  nonassessable  upon
issuance  against full payment of the  purchase price therefor. Unless otherwise
specified in  the  Prospectus Supplement  relating  to a  particular  series  of
Preferred  Stock, each  series of Preferred  Stock will  rank on a  parity as to
dividends and  liquidation rights  in all  respects with  each other  series  of
Preferred Stock (other than the Junior Participating Preferred Stock).
 
DIVIDEND RIGHTS
 
    Holders  of the Preferred Stock of each  series will be entitled to receive,
when, as and if declared by the Board of Directors of the Company, out of  funds
legally  available therefor, cash dividends  at such rates and  on such dates as
are set forth in the Prospectus Supplement relating to such series of  Preferred
Stock.  Different series of the Preferred Stock  may be entitled to dividends at
different rates or based upon different methods of determination. Such rate  may
be  fixed or variable or both. Each such dividend will be payable to the holders
of record as they appear on the stock books of the Company on such record  dates
as  will be fixed by the Board of  Directors of the Company or a duly authorized
committee thereof.  Dividends  on any  series  of  the Preferred  Stock  may  be
cumulative  or noncumulative, as provided  in the Prospectus Supplement relating
thereto.
 
RIGHTS UPON LIQUIDATION
 
    In the event  of any  voluntary or involuntary  liquidation, dissolution  or
winding up of the Company, the holders of each series of Preferred Stock will be
entitled  to receive out of assets of  the Company available for distribution to
stockholders, before any  distribution of assets  is made to  holders of  Common
Stock or any other class of stock ranking junior to such series of the Preferred
Stock upon liquidation, liquidating distributions in the amount set forth in the
Prospectus  Supplement relating to such series of Preferred Stock plus an amount
equal to accrued and unpaid dividends for the then current dividend period  and,
if  such series of the  Preferred Stock is cumulative,  for all dividend periods
prior thereto, all  as set forth  in the Prospectus  Supplement with respect  to
such shares.
 
REDEMPTION
 
    The  terms, if any,  on which shares of  a series of  Preferred Stock may be
subject to optional or mandatory  redemption, in whole or  in part, will be  set
forth in the Prospectus Supplement relating to such series.
 
CONVERSION
 
    The  terms, if  any, on which  shares of  any series of  Preferred Stock are
convertible into Common  Stock will be  set forth in  the Prospectus  Supplement
relating thereto. Such terms may include provisions
 
                                       17

for  conversion, either mandatory, at the option of the holder, or at the option
of the  Company, in  which case  the  number of  shares of  Common Stock  to  be
received  by the holders of Preferred Stock would be calculated as of a time and
in the manner stated in the Prospectus Supplement.
 
TRANSFER AGENT AND REGISTRAR
 
    The transfer  agent,  registrar  and dividend  disbursement  agent  for  the
Preferred  Stock will be designated in the applicable Prospectus Supplement. The
registrar for shares of Preferred Stock will send notices to shareholders of any
meetings at  which  holders of  the  Preferred Stock  have  the right  to  elect
directors of the Company or to vote on any other matter.
 
VOTING RIGHTS
 
    The  holders  of Preferred  Stock of  a  series offered  hereby will  not be
entitled to vote except  as indicated in the  Prospectus Supplement relating  to
such series of Preferred Stock or as required by applicable law.
 
                          DESCRIPTION OF COMMON STOCK
 
GENERAL
 
    Subject  to  the  rights of  the  holders  of any  shares  of  the Company's
Preferred Stock which may  at the time be  outstanding, holders of Common  Stock
are  entitled to  such dividends as  the Board  of Directors may  declare out of
funds legally  available therefor.  The  holders of  Common Stock  will  possess
exclusive  voting  rights in  the Company,  except  to the  extent the  Board of
Directors specifies voting  power with  respect to any  Preferred Stock  issued.
Except  as hereinafter  described, holders of  Common Stock are  entitled to one
vote for each share  of Common Stock,  but will not have  any right to  cumulate
votes  in the election of directors. In the event of liquidation, dissolution or
winding up of the Company, the holders of Common Stock are entitled to  receive,
after  payment of all of the Company's debts  and liabilities and of all sums to
which holders of any  Preferred Stock may be  entitled, the distribution of  any
remaining  assets  of the  Company.  Holders of  the  Common Stock  will  not be
entitled to preemptive rights  with respect to any  shares which may be  issued.
Any  shares of Common Stock sold hereunder will be fully paid and non-assessable
upon issuance against full payment of the purchase price therefor. First Chicago
Trust Company of New York is the transfer agent for the Common Stock. The Common
Stock is listed on the  New York Stock Exchange  and the Pacific Stock  Exchange
under the symbol "UNM."
 
CERTAIN PROVISIONS
 
    The  provisions of  the Company's  Certificate of  Incorporation and By-Laws
which are summarized below may be deemed to have an anti-takeover effect and may
delay, defer or prevent  a tender offer or  takeover attempt that a  stockholder
might  consider in  such stockholder's  best interest,  including those attempts
that might result  in a premium  over the market  price for the  shares held  by
stockholders.
 
    CLASSIFIED BOARD.  The Board of Directors is divided into three classes that
are  elected for staggered  three-year terms. A  director may be  removed by the
stockholders, but  only for  cause, and  only  by the  affirmative vote  of  the
holders,  voting as a single class, of 80%  or more of the total number of votes
entitled to be cast by all holders  of the voting stock which shall include  all
capital  stock  of  the Company  which  by its  terms  may vote  on  all matters
submitted to stockholders of the Company generally.
 
    ISSUANCE OF PREFERRED STOCK.  Pursuant to the Certificate of  Incorporation,
the  Board  of Directors  by  resolution may  establish  one or  more  series of
Preferred Stock  having  such number  of  shares, designation,  relative  voting
rights,   dividend  rates,   liquidation  and  other   rights,  preferences  and
limitations as  may be  fixed by  the  Board of  Directors without  any  further
stockholder  approval. Such  rights, preferences, privileges  and limitations as
may be  established  could have  the  effect  of impeding  or  discouraging  the
acquisition of control of the Company.
 
                                       18

    BUSINESS  COMBINATIONS.  In  addition, the Certificate  of Incorporation and
By-Laws of the Company contain  supermajority voting provisions relating to  the
approval  of business  combinations with  certain stockholders.  Pursuant to the
Company's Certificate  of Incorporation,  any Business  Combination (as  defined
therein,  which term  includes a  merger, sale of  all or  substantially all its
assets, the  adoption  of  a  plan  of  liquidation  and  similar  extraordinary
corporate  transactions)  with  (i)  any person  (other  than  the  Company, its
subsidiaries, certain employee benefit plans of the Company and the trustees  of
such  plans) who is the beneficial owner of 10% or more of the UNUM Voting Stock
(as defined below)  or (ii)  any person  who is  an Affiliate  or Associate  (as
defined  in Rule  12b-2 of  the Exchange  Act) of  the Company  and who  was the
beneficial owner of 10% or more of the UNUM Voting Stock at any time in the  two
years  prior  to the  date in  question  (each such  person, a  "UNUM Interested
Stockholder") must  be approved  by a  supermajority vote,  unless the  Business
Combination  has  been approved  by the  vote  of a  majority of  the Continuing
Directors (as defined below) of the  Company's Board of Directors. "UNUM  Voting
Stock" means all capital stock of the Company which by its terms may vote on all
matters   submitted  to  stockholders  of  the  Company  generally.  "Continuing
Director" means any Board of  Directors member who while  serving as a Board  of
Directors  member is not an Affiliate or Associate or representative of the UNUM
Interested Stockholder and who was a  Board of Directors member before the  UNUM
Interested Stockholder became such and includes certain successors to such Board
of   Directors  members.  The  required   supermajority  vote  consists  of  the
affirmative vote of the  holders of (i)  80% or more of  the UNUM Voting  Stock,
voting together as a single class, and (ii) at least a majority of the shares of
UNUM  Voting Stock not held by  the UNUM Interested Stockholder, voting together
as a single class.
 
    AMENDMENTS TO THE CERTIFICATE  OF INCORPORATION.   Under the Certificate  of
Incorporation,  the  amendment  of,  repeal  of  or  adoption  of  any provision
inconsistent  with  certain  provisions  of  the  Certificate  of  Incorporation
relating  to (i) the election of the  Board of Directors, its powers and related
matters requires the  affirmative vote of  the holders  of at least  80% of  the
outstanding  UNUM  Voting Stock,  voting together  as a  single class,  and (ii)
Business Combinations with UNUM Interested  Stockholders and the required  votes
for amendments of the Certificate of Incorporation requires the affirmative vote
of  the holders specified  in clause (i)  above and the  affirmative vote of the
holders of at least a majority of the outstanding UNUM Voting Stock which is not
beneficially owned  by any  UNUM Interested  Stockholder, voting  together as  a
single  class. The above  supermajority voting requirements do  not apply to any
amendment, repeal  or adoption  recommended by  the Board  of Directors  of  the
Company  if a majority of  the Board of Directors of  the Company then in office
consists of persons who would be eligible to serve as Continuing Directors.
 
    AMENDMENTS TO THE BY-LAWS.   The Certificate of Incorporation provides  that
the  By-Laws may be amended  by the affirmative vote  of a majority of directors
present at a meeting of the Board of  Directors at which a quorum is present  or
by  the affirmative vote of the holders of  at least 80% of all outstanding UNUM
Voting Stock, voting together as a single class.
 
    STOCKHOLDER PROPOSAL PROCEDURES.   The By-Laws  require any stockholder  who
wants  to present a proposal for action by the stockholders at an annual meeting
to deliver a written  notice to the  Secretary of the Company.  To be timely,  a
stockholder's  notice  must be  delivered  to, or  mailed  and received  at, the
principal executive offices of the Company, not less than 60 days nor more  than
90  days prior  to the  date of the  annual meeting,  unless less  than 75 days'
notice or prior public disclosure of the date of such meeting has been given  or
made  to the stockholders, in which case a stockholder's notice must be received
no later than the close of business on  the 15th day following the day on  which
such notice was mailed or such disclosure was made.
 
SHARE PURCHASE RIGHTS PLAN
 
    On  March  13,  1992,  the  Board of  Directors  of  the  Company  adopted a
stockholder rights plan  and declared a  dividend distribution of  one right  (a
"Right") for each outstanding share of Common Stock to
 
                                       19

stockholders  of record at the  close of business on  March 23, 1992. Each Right
entitles the registered holder to purchase from the Company a unit consisting of
one one-hundredth of a share (a "Unit") of Junior Participating Preferred Stock,
at a  purchase price  of $150  per Unit,  subject to  adjustment (the  "Purchase
Price"). The terms of the Junior Participating Preferred Stock are such that one
Unit is essentially equivalent to one share of Common Stock. The description and
terms  of the Rights are set forth in  a Rights Agreement, dated as of March 13,
1992 and  amended as  of June  19, 1996  (as amended,  the "Rights  Agreement"),
between the Company and First Chicago Trust Company of New York, as rights agent
(the "Rights Agent").
 
    Initially,   the  Rights  are  attached  to  all  outstanding  Common  Stock
certificates,  and   no  separate   certificates  evidencing   Rights   ("Rights
Certificates")  are distributed. The Rights will  separate from the Common Stock
and a "Distribution  Date" will  occur upon  the earlier  of (i)  ten (10)  days
following  a  public  announcement  that  a person  or  group  of  affiliated or
associated persons (an "Acquiring Person")  has acquired, or obtained the  right
to  acquire, beneficial ownership  of 10% or  more of the  outstanding shares of
Common Stock, except for persons or a group of affiliated or associated  persons
who  become the  beneficial owner of  10% or  more of the  outstanding shares of
Common Stock solely as a result of a reduction in the number of shares of Common
Stock outstanding  due to  a repurchase  of shares  by the  Company unless  such
person or group thereafter acquires additional shares representing 1% or more of
the  outstanding Common  Stock (the "Stock  Acquisition Date") or  (ii) ten (10)
business days  (or  such  later date  as  may  be determined  by  the  Board  of
Directors)  following the announcement of a  tender offer or exchange offer that
would result  in a  person or  group beneficially  owning 10%  or more  of  such
outstanding  shares of Common Stock.  However, if the Board  of Directors of the
Company determines that any  person who would otherwise  be an Acquiring  Person
has  become such  inadvertently, then such  person will not  become an Acquiring
Person if certain conditions are satisfied, including divestiture by such person
of beneficial ownership of the shares of Common Stock that would have  otherwise
caused such person to become an Acquiring Person.
 
    Until  the Distribution Date, (i) the Rights will be evidenced by the Common
Stock certificates and will be transferred with and only with such Common  Stock
certificates,  (ii) new  Common Stock certificates  issued after  March 23, 1992
contain a notation incorporating  the Rights Agreement  by reference, and  (iii)
the surrender for transfer of any certificates for Common Stock outstanding will
also  constitute the  transfer of  the Rights  associated with  the Common Stock
represented by  such certificates.  The  Rights are  not exercisable  until  the
Distribution  Date and will expire  at the close of  business on March 13, 2002,
unless earlier  redeemed by  the  Company as  described below  (the  "Expiration
Date").
 
    In  the event that (i) a Person becomes an Acquiring Person (except pursuant
to an offer for all outstanding shares of Common Stock which at least a majority
of the members of the Board of Directors who are not officers of the Company and
who are not representatives, nominees, affiliates or associates of an  Acquiring
Person  determine  to be  fair to  and otherwise  in the  best interests  of the
Company and its stockholders  (a "Fair Offer")) or  (ii) an Acquiring Person  or
any  of its affiliates or associates shall  merge into or otherwise combine with
the Company in a transaction in  which the Company is the surviving  corporation
and  the Common Stock remains outstanding and  unchanged, each holder of a Right
will thereafter have the right to  receive, upon exercise, Common Stock (or,  in
certain  circumstances, cash, property  or other securities of  the Company or a
reduction in the Purchase Price) having a value equal to two times the  exercise
price  of  the  Right.  Notwithstanding  any  of  the  foregoing,  following the
occurrence of any of  the events set  forth in this  paragraph, all Rights  that
are,  or (under certain  circumstances specified in  the Rights Agreement) were,
beneficially owned by  an Acquiring Person  or an associate  or affiliate of  an
Acquiring  Person will  be null  and void.  However, Rights  are not exercisable
following the occurrence of any of the events set forth in this paragraph  until
such  time as the  Rights are no longer  redeemable by the  Company as set forth
below.
 
    In the event that, at any time following the Stock Acquisition Date, (i) the
Company is acquired  in a merger  or other business  combination transaction  in
which the Company is not the surviving corporation
 
                                       20

(other  than a  merger described  in the preceding  paragraph or  a merger which
follows, and is at  the same price  as, a Fair  Offer), or (ii)  50% or more  of
UNUM's  assets or earning power  is sold or transferred,  each holder of a Right
(except Rights which previously  have become null and  void as set forth  above)
shall  thereafter have the right to receive,  upon exercise, common stock of the
acquiring company having a value  equal to two times  the exercise price of  the
Right. The events set forth in this paragraph and in the preceding paragraph are
referred to as the "Triggering Events."
 
    At  any time after there is an Acquiring Person and prior to the acquisition
by such Acquiring Person  of 50% or  more of the  outstanding Common Stock,  the
Board  of Directors  may exchange  the Rights  (other than  Rights owned  by the
Acquiring Person which have become  null and void), in whole  or in part, at  an
exchange  ratio of one share of Common Stock or one Unit of Junior Participating
Preferred Stock (or a share or unit of another series of the Company's preferred
stock having equivalent rights, preferences  and privileges) per Right  (subject
to adjustment).
 
    At  any time until ten  (10) days following the  Stock Acquisition Date, the
Company may redeem the Rights in whole, but not in part, at a price of $.01  per
Right  (the "Redemption Price"), which is payable in cash, Common Stock or other
consideration deemed appropriate by the Board of Directors. Immediately upon the
action of the Board of Directors  ordering redemption of the Rights, the  Rights
will  terminate and the only  right of the holders of  Rights will be to receive
the Redemption Price.
 
    The Purchase Price payable, and the number of shares of Junior Participating
Preferred Stock or other securities or  property issuable, upon exercise of  the
Rights are subject to adjustment from time to time to prevent dilution.
 
    Until a Right is exercised, the holder thereof, as such, will have no rights
as  a stockholder  of the Company,  including, without limitation,  the right to
vote  or   to  receive   dividends.  Stockholders   may,  depending   upon   the
circumstances,  recognize taxable  income in  the event  that the  Rights become
exercisable for Common Stock (or other consideration) or for common stock of the
acquiring company as set forth above.
 
    The Rights  have  certain  anti-takeover  effects.  The  Rights  will  cause
substantial  dilution to a person or group  that attempts to acquire the Company
in a manner which causes  the Rights to become  exercisable unless the offer  is
conditioned  on  substantially all  the  Rights being  acquired.  This potential
dilution may have the effect of delaying, deferring or discouraging attempts  to
acquire  control of the Company which are not approved by the Company's Board of
Directors. However, the  Rights should not  interfere with any  merger or  other
business combination approved by the Company's Board of Directors.
 
DESCRIPTION OF JUNIOR PARTICIPATING PREFERRED STOCK
 
    GENERAL.    In connection  with the  Rights  Agreement, 1,000,000  shares of
Junior Participating  Preferred  Stock have  been  reserved and  authorized  for
issuance  by  the  Board  of  Directors of  the  Company.  No  shares  of Junior
Participating Preferred Stock are outstanding as of the date of this Prospectus.
The following  statements with  respect to  the Junior  Participating  Preferred
Stock  do not purport to be complete  and are subject to the detailed provisions
of the Certificate of Incorporation and the certificate of designation  relating
to  the Junior Participating Preferred Stock (the "Certificate of Designation"),
which are  filed  as  exhibits  to the  Registration  Statement  of  which  this
Prospectus is a part.
 
    RANKING.   The Junior Participating Preferred Stock shall rank junior to all
other series of the Company's Preferred Stock as to the payment of dividends and
the distribution of assets,  unless the terms of  any such series shall  provide
otherwise.
 
    DIVIDENDS  AND DISTRIBUTIONS.   Subject to the prior  and superior rights of
the holders of any  shares of any  series of Preferred  Stock ranking prior  and
superior  to the shares of Junior  Participating Preferred Stock with respect to
dividends, the holders of shares  of Junior Participating Preferred Stock  shall
be  entitled to receive, when, as and if  declared by the Board of Directors out
of funds legally available for
 
                                       21

that purpose, quarterly dividends payable in  cash on the 19th day of  February,
May,  August and November in each year  (each such date being referred to herein
as "Quarterly Dividend Payment Date") commencing on the first Quarterly Dividend
Payment Date after  the first  issuance of  a share or  fraction of  a share  of
Junior  Participating Preferred  Stock, in an  amount per share  (rounded to the
nearest cent) equal to the  greater of (a) $5.00  or (b) (subject to  adjustment
upon  certain dilutive events) 100  times the aggregate per  share amount of all
cash dividends, and 100 times the  aggregate per share amount (payable in  kind)
of  all non-cash dividends or other  distributions other than a dividend payable
in shares of Common Stock or a  subdivision of the outstanding shares of  Common
Stock  (by reclassification or  otherwise), declared on  the Common Stock, since
the immediately preceding Quarterly Dividend  Payment Date, or, with respect  to
the first Quarterly Dividend Payment Date, since the first issuance of any share
or fraction of a share of Junior Participating Preferred Stock.
 
    The  Company  shall  declare  a  dividend  or  distribution  on  the  Junior
Participating Preferred  Stock  immediately  after it  declares  a  dividend  or
distribution  on the Common  Stock (other than  a dividend payable  in shares of
Common Stock); provided  that, in the  event no dividend  or distribution  shall
have  been declared on the Common Stock  during the period between any Quarterly
Dividend Payment Date and the next subsequent Quarterly Dividend Payment Date, a
dividend of $5.00 per  share on the Junior  Participating Preferred Stock  shall
nevertheless be payable on such subsequent Quarterly Dividend Payment Date.
 
    VOTING  RIGHTS.   The holders  of shares  of Junior  Participating Preferred
Stock shall have  the following voting  rights: (a) subject  to adjustment  upon
certain  dilutive  events, each  share of  Junior Participating  Preferred Stock
shall entitle the holder thereof to 100 votes on all matters submitted to a vote
of the stockholders  of the  Company; (b) except  as otherwise  provided by  the
Certificate  of  Designation  or  by  law,  the  holders  of  shares  of  Junior
Participating Preferred Stock and  the holders of shares  of Common Stock  shall
vote together as one class on all matters submitted to a vote of stockholders of
the  Company;  and (c)  if at  any  time dividends  on any  Junior Participating
Preferred Stock shall  be in arrears  in an  amount equal to  six (6)  quarterly
dividends  thereon, the occurrence of such  contingency shall mark the beginning
of a period  (herein called a  "default period") which  shall extend until  such
time  when all accrued and unpaid  dividends for all previous quarterly dividend
periods and for the  current quarterly dividend period  on all shares of  Junior
Participating Preferred Stock then outstanding shall have been declared and paid
or  set apart for payment. During each  default period, all holders of Preferred
Stock (including  holders  of the  Junior  Participating Preferred  Stock)  with
dividends  in arrears in an amount equal to six (6) quarterly dividends thereon,
voting as a class, irrespective of series, shall have the right to elect two (2)
Directors, until the expiration of a default period.
 
    LIQUIDATION, DISSOLUTION OR WINDING UP.  Upon any liquidation (voluntary  or
otherwise),  dissolution or winding up of  the Company, no distribution shall be
made to the holders of shares of stock ranking junior (either as to dividends or
upon liquidation,  dissolution  or  winding  up)  to  the  Junior  Participating
Preferred  Stock  unless,  prior  thereto,  the  holders  of  shares  of  Junior
Participating Preferred Stock shall have received $250 per share, plus an amount
equal to accrued and unpaid dividends and distributions thereon, whether or  not
declared,  to the date of such  payment (the "Series A Liquidation Preference").
Following the payment of the full amount of the Series A Liquidation Preference,
no additional distributions  shall be made  to the holders  of shares of  Junior
Participating  Preferred Stock unless,  prior thereto, the  holders of shares of
Common Stock shall have received an  amount per share (the "Common  Adjustment")
equal  to  the  quotient  obtained  by dividing  (i)  the  Series  A Liquidation
Preference by (ii)  100 (as  appropriately adjusted  to reflect  such events  as
stock  splits, stock dividends and recapitalizations  with respect to the Common
Stock) (such number in  clause (ii) immediately above  being referred to as  the
"Adjustment  Number"). Following the payment of the  full amount of the Series A
Liquidation Preference and the Common  Adjustment in respect of all  outstanding
shares  of Junior Participating Preferred  Stock and Common Stock, respectively,
holders of Junior Participating Preferred Stock and
 
                                       22

holders of shares of Common Stock shall receive their ratable and  proportionate
share  of the remaining assets to be  distributed in the ratio of the Adjustment
Number to one (1) with  respect to such Preferred Stock  and Common Stock, on  a
per share basis, respectively.
 
    In  the event,  however, that there  are not sufficient  assets available to
permit  payment  in  full  of  the  Series  A  Liquidation  Preference  and  the
liquidation  preferences of all  other series of preferred  stock, if any, which
rank on  a parity  with  the Junior  Participating  Preferred Stock,  then  such
remaining  assets shall  be distributed  ratably to  the holders  of such parity
shares in proportion to their respective liquidation preferences. In the  event,
however,  that there  are not sufficient  assets available to  permit payment in
full of the Common Adjustment, then  such remaining assets shall be  distributed
ratably to the holders of Common Stock.
 
    CONSOLIDATION,  MERGER,  ETC.   In  case the  Company  shall enter  into any
consolidation, merger, combination or other  transaction in which the shares  of
Common  Stock are exchanged for or changed  into other stock or securities, cash
and/or any  other  property,  then  in  any such  case,  the  shares  of  Junior
Participating  Preferred Stock shall at the  same time be similarly exchanged or
changed in an  amount per  share (subject  to adjustment  upon certain  dilutive
events)  equal  to 100  times the  aggregate amount  of stock,  securities, cash
and/or any other property (payable in kind),  as the case may be, into which  or
for which each share of Common Stock is changed or exchanged.
 
    REDEMPTION.   The outstanding shares of Junior Participating Preferred Stock
may be redeemed at  the option of the  Board of Directors in  whole, but not  in
part,  at any time, or from time to time, at a cash price per share equal to 105
percent of (i)  the product of  the Adjustment Number  times the Average  Market
Value  (as such term is hereinafter defined)  of the Common Stock, plus (ii) all
dividends which on the redemption date have accrued on the shares to be redeemed
and have not been paid, or declared and a sum sufficient for the payment thereof
set apart, without interest.  The "Average Market Value"  is the average of  the
closing  sale prices  of the Common  Stock during the  30-day period immediately
preceding the date before the redemption date on the Composite Tape for New York
Stock Exchange Listed Stocks, or, if such  stock is not quoted on the  Composite
Tape,  on the New York Stock  Exchange, or, if such stock  is not listed on such
Exchange, on the  principal United States  securities exchange registered  under
the Exchange Act, on which such stock is listed, or, if such stock is not listed
on  any such exchange, the average of the  closing sale prices with respect to a
share of  Common Stock  during such  30-day period,  as quoted  on the  National
Association  of  Securities Dealers,  Inc.  Automated Quotations  System  or any
system then in use,  or, if no  such quotations are  available, the fair  market
value of the Common Stock as determined by the Board of Directors in good faith.
 
                            DESCRIPTION OF WARRANTS
 
    The  Company  may  issue  Warrants,  including  Warrants  to  purchase  Debt
Securities, Preferred Stock, Common  Stock or other  securities of the  Company.
Warrants may be issued independently or together with any such securities of the
Company  and may be attached to or separate from such securities of the Company.
The Warrants  are  to  be  issued under  warrant  agreements  (each  a  "Warrant
Agreement")  to be entered into between the Company and a bank or trust company,
as warrant  agent (the  "Warrant  Agent"), all  as shall  be  set forth  in  the
Prospectus Supplement relating to Warrants being offered pursuant thereto.
 
WARRANTS
 
    The  applicable Prospectus  Supplement will  describe the  terms of Warrants
offered thereby, the Warrant Agreement relating to such Warrants and the warrant
certificates representing such Warrants, including the following: (1) the  title
of  such Warrants; (2) the securities of the Company for which such Warrants are
exercisable; (3) the aggregate number of such Warrants; (4) the price or  prices
at which such Warrants will be issued; (5) the currency or currencies, including
composite  currencies or currency units, in which the price of such Warrants may
be   payable;    (6)    the    procedures    and    conditions    relating    to
 
                                       23

the  exercise of  such Warrants;  (7) the designation  and terms  of any related
securities of the Company with which such Warrants are issued, and the number of
such Warrants issued with each such security; (8) the date, if any, on and after
which such Warrants and the related securities of the Company will be separately
transferable; (9) the date  on which the right  to exercise such Warrants  shall
commence,  and the date  on which such  right shall expire;  (10) the maximum or
minimum number of  such Warrants  which may  be exercised  at any  time; (11)  a
discussion  of material United States Federal income tax considerations, if any;
(12) any other  terms of  such Warrants  and terms,  procedures and  limitations
relating  to the exercise of such Warrants; and (13) the terms of the securities
of the Company purchasable upon exercise of such Warrants.
 
    Warrant certificates  will  be exchanged  for  new warrant  certificates  of
different  denominations, and Warrants  may be exercised  at the corporate trust
office of the  Warrant Agent  or any other  office indicated  in the  Prospectus
Supplement.  Prior  to  the  exercise of  their  Warrants,  holders  of Warrants
exercisable for Debt Securities will  not have any of  the rights of holders  of
the  Debt Securities purchasable upon such exercise  and will not be entitled to
payments of principal  (or premium, if  any) or  interest, if any,  on the  Debt
Securities  purchasable  upon  such exercise.  Prior  to the  exercise  of their
Warrants for shares of Preferred Stock or Common Stock, holders of such Warrants
will not have  any rights  of holders  of the  Preferred Stock  or Common  Stock
purchasable upon such exercise and will not be entitled to dividend payments, if
any,  or voting rights of  the Preferred Stock or  Common Stock purchasable upon
such exercise.
 
EXERCISE OF WARRANTS
 
    Each Warrant will entitle the holder  of Warrants to purchase for cash  such
principal  amount or such number  of securities of the  Company at such exercise
price as shall in each case be set forth in, or be determinable as set forth in,
the Prospectus Supplement relating  to the Warrants  offered thereby. After  the
close of business on the expiration date, unexercised Warrants will become void.
 
    Warrants may be exercised as set forth in the Prospectus Supplement relating
to  the  Warrants  offered thereby.  Upon  receipt  of payment  and  the warrant
certificate properly completed and duly  executed at the corporate trust  office
of the Warrant Agent or any other office indicated in the Prospectus Supplement,
the  Company will,  as soon as  practicable, forward  the securities purchasable
upon such exercise. If less than all of the Warrants represented by such warrant
certificate are exercised,  a new  warrant certificate  will be  issued for  the
remaining Warrants.
 
                             FOREIGN CURRENCY RISKS
 
GENERAL
 
    EXCHANGE  RATES AND  EXCHANGE CONTROLS.   An  investment in  Debt Securities
denominated in other than  U.S. dollars entails significant  risks that are  not
associated  with a similar investment in a security denominated in U.S. dollars.
Such risks include, without limitation,  the possibility of significant  changes
in  rates of exchange between the U.S. dollar and the various foreign currencies
or composite currencies, and the  possibility of the imposition or  modification
of  foreign exchange  controls by either  the U.S. or  foreign governments. Such
risks generally depend on economic and  political events over which the  Company
has  no control. In recent years, rates  of exchange between the U.S. dollar and
certain foreign currencies have been highly volatile, and such volatility may be
expected to continue in the future. Fluctuations in any particular exchange rate
that have  occurred in  the past  are not  necessarily indicative,  however,  of
fluctuations  in the rate that  may occur during the  term of any Debt Security.
Depreciation of the Specified Currency other than U.S. dollars against the  U.S.
dollar  would result in a decrease in  the effective yield of such Debt Security
below its coupon rate, and  in certain circumstances could  result in a loss  to
the investor on a U.S. dollar basis.
 
    Governments  have imposed  from time  to time and  may in  the future impose
exchange controls that could affect exchange  rates as well as the  availability
of a specified foreign currency at a Debt Security's
 
                                       24

maturity. Even if there are no actual exchange controls, it is possible that the
Specified  Currency for any  particular Debt Security would  not be available at
such Debt Security's maturity. In that  event, the Company will repay such  Debt
Security at maturity in U.S. dollars on the basis of the most recently available
Exchange Rate.
 
    This  Prospectus does not  describe all the  risks of an  investment in Debt
Securities denominated in other than U.S. dollars. Prospective investors  should
consult  their own financial and  legal advisors as to  the risks entailed by an
investment in  Debt Securities  denominated  in other  than U.S.  dollars.  Debt
Securities  denominated  in  other  than U.S.  dollars  are  not  an appropriate
investment  for  investors  who  are  unsophisticated  about  foreign   currency
transactions.
 
    Currently,  there are limited facilities in the United States for conversion
of U.S. dollars into certain foreign currencies, and vice versa.
 
    Unless otherwise  specified in  the Prospectus  Supplement, Debt  Securities
denominated  in other than U.S.  dollars or European currency  units will not be
sold in, or to residents of, the country issuing the Specified Currency in which
particular Debt Securities are  denominated. The information  set forth in  this
Prospectus   is  directed  to  prospective  purchasers  who  are  United  States
residents, and the  Company disclaims any  responsibility to advise  prospective
purchasers who are residents of countries other than the United States as to any
matters  that  may  affect the  purchase,  holding,  or receipt  of  payments of
principal of and interest  on the Debt Securities.  Such persons should  consult
their own financial and legal advisors with regard to such matters.
 
    GOVERNING  LAW AND JUDGMENTS.   The Debt Securities will  be governed by and
construed in  accordance with  the laws  of the  State of  New York.  Under  the
Judiciary  Law of the State of  New York, a judgment in  an action based upon an
obligation denominated in a currency other than U.S. dollars will be rendered in
the foreign  currency  of the  underlying  obligation and  converted  into  U.S.
dollars  at the  rate of  exchange prevailing on  the date  of the  entry of the
judgment or decree.
 
EXCHANGE RATE AND CONTROLS FOR SPECIFIED CURRENCIES
 
    For any Debt Security denominated in other than U.S. dollars, the Prospectus
Supplement relating to such Debt Securities will contain information  concerning
exchange rates. The information concerning exchange rates will be furnished as a
matter  of information only and should not be regarded as indicative of the rate
of or trends in future fluctuations in currency exchange rates.
 
                              PLAN OF DISTRIBUTION
 
    The Company may  sell Securities to  or through underwriters,  and also  may
sell Securities directly to other purchasers or through agents.
 
    The  distribution of the Securities may be effected from time to time in one
or more transactions at  a fixed price  or prices, which may  be changed, or  at
market  prices  prevailing  at the  time  of  sale, at  prices  related  to such
prevailing market prices or at negotiated prices.
 
    In  connection  with  the  sale  of  Securities,  underwriters  may  receive
compensation  from the Company  or from purchasers of  Securities, for whom they
may act  as agents,  in  the form  of  discounts, concessions,  or  commissions.
Underwriters  may sell  Securities to or  through dealers, and  such dealers may
receive compensation in the form of discounts, concessions, or commissions  from
the underwriters and/or commissions from the purchasers for whom they may act as
agents.  Underwriters, dealers, and agents  that participate in the distribution
of Securities may be deemed to be underwriters, and any discounts or commissions
they receive from the Company, and any  profit on the resale of Securities  they
realize  may be deemed  to be underwriting discounts  and commissions, under the
Securities Act. Any such underwriter or  agent will be identified, and any  such
compensation  received from  the Company  will be  described, in  the Prospectus
Supplement.
 
                                       25

    Each series of Securities  will be a new  issue with no established  trading
market,  other  than the  Common Stock  which is  listed on  the New  York Stock
Exchange and the  Pacific Stock Exchange.  Any Common Stock  sold pursuant to  a
Prospectus  Supplement will  be listed  on such  exchanges, subject  to official
notice of issuance. The Company may elect to list any series of Debt Securities,
Preferred Stock or Warrants on an exchange, but is not obligated to do so. It is
possible that  one  or more  underwriters  may make  a  market in  a  series  of
Securities,  but will not be  obligated to do so  and may discontinue any market
making at any time without  notice. Therefore, no assurance  can be given as  to
the liquidity of the trading market for the Securities.
 
    Under  agreements  the Company  may enter  into, underwriters,  dealers, and
agents who  participate in  the  distribution of  Securities maybe  entitled  to
indemnification   by   the  Company   against  certain   liabilities,  including
liabilities under the Securities Act.
 
    Underwriters, dealers and agents may engage in transactions with, or perform
services for,  or  be  customers of,  the  Company  in the  ordinary  course  of
business.
 
    If  so indicated  in the Prospectus  Supplement, the  Company will authorize
underwriters or other persons acting as  the Company's agents to solicit  offers
by  certain institutions  to purchase  Securities from  the Company  pursuant to
contracts providing for payment and delivery on a future date. Institutions with
which such contracts may be made include commercial and savings banks, insurance
companies, pension  funds,  investment  companies,  educational  and  charitable
institutions  and others, but in all cases such institutions must be approved by
the Company. The obligations  of any purchaser under  any such contract will  be
subject  to the condition that  the purchase of the  Securities shall not at the
time of delivery be prohibited under the laws of the jurisdiction to which  such
purchaser  is subject. The underwriters and such  other agents will not have any
responsibility in respect of the validity or performance of such contracts.
 
                           VALIDITY OF THE SECURITIES
 
    The validity  of the  Securities will  be  passed upon  for the  Company  by
Skadden,  Arps, Slate, Meagher &  Flom, New York, New  York. The validity of the
Securities in connection with any offering  thereof will be passed upon for  the
Company  by  Kevin  J. Tierney,  Senior  Vice President,  Secretary  and General
Counsel of the Company and  by Skadden, Arps, Slate,  Meagher & Flom, New  York,
New  York  with  respect  to  certain  matters of  New  York  law,  and  for the
underwriters or agents by Sullivan &  Cromwell, New York, New York. Mr.  Tierney
owns less than one percent of the Company's Common Stock.
 
                                    EXPERTS
 
    The  consolidated financial statements  of the Company  and its subsidiaries
included in the Company's Annual Report on Form 10-K for the year ended December
31, 1995, have been incorporated herein by reference in reliance upon the report
of  Coopers  &   Lybrand  L.L.P,  independent   certified  public   accountants,
incorporated by reference herein, and upon the authority of said firm as experts
in accounting and auditing.
 
                                       26

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    NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS OTHER THAN THOSE CONTAINED OR INCORPORATED BY REFERENCE IN ANY
PRICING SUPPLEMENT, THIS PROSPECTUS SUPPLEMENT, OR THE PROSPECTUS, AND, IF GIVEN
OR MADE, SUCH INFORMATION OR REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING
BEEN AUTHORIZED. ANY PRICING SUPPLEMENT, THIS PROSPECTUS SUPPLEMENT, AND THE
PROSPECTUS DO NOT CONSTITUTE AN OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO
BUY ANY SECURITIES OTHER THAN THE SECURITIES DESCRIBED IN THIS PROSPECTUS
SUPPLEMENT OR AN OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO BUY SUCH
SECURITIES IN ANY CIRCUMSTANCES IN WHICH SUCH OFFER OR SOLICITATION IS UNLAWFUL.
NEITHER THE DELIVERY OF ANY PRICING SUPPLEMENT, THIS PROSPECTUS SUPPLEMENT, OR
THE PROSPECTUS NOR ANY SALE MADE HEREUNDER OR THEREUNDER SHALL, UNDER ANY
CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THERE HAS BEEN NO CHANGE IN THE
AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF OR THAT THE INFORMATION CONTAINED,
OR INCORPORATED BY REFERENCE, HEREIN OR THEREIN IS CORRECT AS OF ANY TIME
SUBSEQUENT TO ITS DATE.
 
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                               TABLE OF CONTENTS
                             PROSPECTUS SUPPLEMENT
 


                                                       PAGE
                                                     ---------
                                                  
Description of Notes...............................        S-2
United States Taxation.............................       S-17
Supplemental Plan of Distribution..................       S-25
Validity of Notes..................................       S-26
                          PROSPECTUS
Available Information..............................          2
Incorporation of Certain Documents by Reference....          2
The Company........................................          3
Selected Consolidated Financial Data of the
 Company...........................................          6
Selected Consolidated Segment Income Statement Data
 of the Company....................................          7
Use of Proceeds....................................          8
Description of Debt Securities.....................          8
Description of Capital Stock.......................         16
Description of Preferred Stock.....................         16
Description of Common Stock........................         18
Description of Warrants............................         23
Foreign Currency Risks.............................         24
Plan of Distribution...............................         25
Validity of the Securities.........................         26
Experts............................................         26

 
                                  $250,000,000
 
                                UNUM CORPORATION
 
                               MEDIUM-TERM NOTES,
                                    SERIES C
 
                           DUE FROM 9 MONTHS OR MORE
                               FROM DATE OF ISSUE
 
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                             PROSPECTUS SUPPLEMENT
 
                                  -----------
 
                              GOLDMAN, SACHS & CO.
 
                              MORGAN STANLEY & CO.
       INCORPORATED
 
                                     [LOGO]
 
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