1
 
PROSPECTUS
                                            Filed Pursuant to Rule 424(b)(5)
                                            Registration Statement No. 33-55249 
   
                               20,628,572 SHARES
    
 
                            SEAGATE TECHNOLOGY, INC
 
                                  COMMON STOCK
 
     The shares of Common Stock, $.01 par value per share (the "Common Stock"),
of Seagate Technology, Inc. ("Seagate" or the "Company") covered by this
Prospectus are shares which may be offered and sold, from time to time, for the
account of certain prospective stockholders of the Company (the "Selling
Stockholders") who currently hold the Company's 5% Convertible Subordinated
Debentures Due 2003 (the "Debentures"). See "Selling Stockholders." The shares
of Common Stock covered by this Prospectus are issuable to the Selling
Stockholders upon conversion of the Debentures. All of the shares covered hereby
are to be sold by the Selling Stockholders. The Company will not receive any of
the proceeds from the sale of the shares by the Selling Stockholders.
 
     The Selling Stockholders may from time to time sell the shares of Common
Stock covered by this Prospectus to or through one or more underwriters, and may
also sell shares of Common Stock directly to other purchasers or through agents,
on the Nasdaq National Market in ordinary brokerage transactions, in negotiated
transactions, or otherwise, at market prices prevailing at the time of sale, at
prices related to the then prevailing market prices or at negotiated prices. See
"Plan of Distribution." This Prospectus may not be used to consummate sales of
Common Stock unless accompanied by a Prospectus Supplement which sets forth the
names of any underwriters, dealers or agents involved in the sale of the shares
of Common Stock in respect of which this Prospectus is being delivered, and any
applicable fee, commission or discount arrangements with them.
 
     The Company's Common Stock is traded on the Nasdaq National Market under
the symbol "SGAT." On August 24, 1994, the last sale price for the Common Stock
as reported on the Nasdaq National Market was $24 1/4 per share.
 
     SEE "RISK FACTORS" FOR A DISCUSSION OF CERTAIN FACTORS THAT SHOULD BE
CONSIDERED BY PROSPECTIVE PURCHASERS OF THE COMMON STOCK OFFERED HEREBY.
 
                            ------------------------
 
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 SEPTEMBER 19, 1994
    
   2
 
                             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"). Such reports, proxy and
information statements and other information may be inspected and copied at the
public reference facilities maintained by the Commission at 450 Fifth Street,
N.W., Washington, D.C. 20549, and at the following Regional Offices of the
Commission: New York Regional Office, Seven World Trade Center, New York, New
York 10048, and Chicago Regional Office, 500 West Madison Street, Chicago,
Illinois 60661. Copies of such material can be obtained from the Public
Reference Section of the Commission, 450 Fifth Street, N.W., Washington, D.C.
20549 upon payment of the prescribed fees. The Common Stock of the Company is
quoted on the Nasdaq National Market. Reports, proxy and information statements
and other information concerning the Company may be inspected at the National
Association of Securities Dealers, Inc. at 1735 K Street, N.W., Washington, D.C.
20006.
 
     This Prospectus constitutes a part of a Registration Statement on Form S-3
(herein, together with all amendments and exhibits, referred to as the
"Registration Statement") filed by the Company with the Commission under the
Securities Act of 1933, as amended (the "Securities Act"). 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. For further information with respect to the Company and the
shares covered by this prospectus, reference is made to the Registration
Statement. Statements contained herein concerning the provisions of any document
are not necessarily complete, and each such statement is qualified in its
entirety by reference to the copy of such document filed with the Commission.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
     The following documents filed by the Company with the Commission are hereby
incorporated by reference in this Prospectus: (i) the Company's Annual Report on
Form 10-K for the fiscal year ended July 1, 1994; (ii) the description of the
Company's Common Stock contained in its Registration Statement on Form 8-A as
filed with the Commission on April 17, 1987; and (iii) the description of the
Company's Preferred Stock Purchase Rights contained in its Registration
Statement on Form 8-A filed with the Commission on November 23, 1988.
 
     All reports and other documents subsequently filed by the Company pursuant
to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this
Prospectus and prior to the termination of this offering shall be deemed to be
incorporated by reference herein and to be a part hereof from the date of filing
of such reports and documents. Any statement incorporated herein shall be deemed
to be modified or superseded for purposes of this Prospectus to the extent that
a statement contained herein, in a Prospectus Supplement or in any other
subsequently filed document which also is or is deemed to be incorporated by
reference herein modifies or supersedes such statement. Any statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of the Registration Statement or this Prospectus.
 
     The Company hereby undertakes to provide without charge to each person,
including any beneficial owner, to whom a copy of this Prospectus has been
delivered, upon written or oral request of such person, a copy of any or all of
the foregoing documents incorporated herein by reference (other than exhibits to
such documents, unless such exhibits are specifically incorporated by reference
into such documents). Requests for such documents should be submitted in writing
to Investor Relations at the Company's principal executive offices at 920 Disc
Drive, Scotts Valley, California 95066 or by telephone at (408) 438-6550.
                            ------------------------
 
                                        2
   3
 
                                  THE COMPANY
 
     Seagate Technology, Inc. ("Seagate" or the "Company") designs, manufactures
and markets a broad line of rigid magnetic disc drives for use in computer
systems ranging from notebook computers and desktop personal computers to
workstations and supercomputers, as well as in multimedia applications such as
digital video and video-on-demand. The Company's products include over 100 rigid
disc drive models with form factors from 2.5 to 5.25 inches and capacities from
130 megabytes to 9 gigabytes. The Company sells its products to original
equipment manufacturers ("OEMs") for inclusion in their computer systems or
subsystems, and to distributors, resellers and dealers. The Company has pursued
a strategy of vertical integration and accordingly designs and manufactures
rigid disc drive components including recording heads, discs, substrates, motors
and custom integrated circuits. Seagate also assembles certain of the key
subassemblies for use in its products including printed circuit board and head
stack assemblies. The Company's products are currently manufactured primarily in
the Far East with limited production in the United States.
 
     In addition to pursuing its core rigid disc drive business, the Company is
broadening its business strategy as a data technology company to more fully
address the markets for storage, retrieval and management of data. In this
regard, the Company has implemented a strategy to sell selected magnetic
recording components including thin-film heads, head stack assemblies and motors
to other manufacturers. The Company is also investigating various opportunities
to invest in software activities in which software might be sold together with
the Company's products or marketed separately to third parties. Finally, the
Company's strategy includes expanding its traditional rigid disc drive business
to include other forms of data storage and retrieval, such as flash memory. The
Company's broadened strategy has included and may continue to include
acquisitions of, investments in and strategic alliances regarding complementary
businesses, products and technologies.
 
     Seagate Technology is a registered trademark of Seagate Technology, Inc.
 
                                        3
   4
 
                                  RISK FACTORS
 
     An investment in shares of the Company's Common Stock being offered hereby
involves a high degree of risk. In addition to the other information provided
elsewhere in this Prospectus or incorporated herein by reference, the following
risk factors should be considered carefully by potential purchasers in
evaluating an investment in the shares of Common Stock covered by this
Prospectus.
 
     Variability of Demand, Price Erosion and Other Characteristics of the Rigid
Disc Drive Industry.  The rigid disc drive industry in which the Company
competes is subject to a number of risks. The demand for rigid disc drive
products depends principally on demand for computer systems, which has
historically been volatile. Changes in demand for computer systems often have an
exaggerated effect on the demand for rigid disc drive products in any given
period, and unexpected slowdowns in demand for computer systems generally cause
sharp declines in demand for rigid disc drive products. The industry has been
characterized by periodic situations in which the supply of rigid disc drives
exceeds demand, resulting in higher than anticipated inventory levels, strong
price competition and significant price erosion. Even during periods of
consistent demand, the industry is characterized by intense competition and
ongoing price erosion over the life of a given rigid disc drive product. The
Company expects that price erosion in the rigid disc drive industry will
continue and that overall unit volumes may not grow sufficiently to result in
material levels of industry-wide revenue growth. In addition, the demand of
rigid disc drive customers for new generations of products has led to short
product life cycles, which requires that industry participants constantly
develop and introduce new rigid disc drive products on a cost effective and
timely basis. The manufacture of rigid disc drive products is difficult and
complex, and it is common in the industry for companies to experience production
difficulties which occasionally create delivery delays and quality problems.
Most rigid disc drive products, including those of the Company, are manufactured
outside of North America and foreign manufacturing is subject to a number of
risks, including changes in government policies, transportation delays, tariffs,
customs duties, fluctuations in foreign exchange rates, and export and tax
controls. For these reasons, as well as those discussed in the following
additional risk factors, an investment in the securities of the Company involves
a high degree of risk.
 
     New Product Development.  The rigid disc drive industry is characterized by
rapidly changing technology, short product life cycles and rapidly changing
customer needs, each of which requires ongoing development and introduction of
new products. The Company believes that its future success will depend upon its
ability to develop, manufacture and market products which meet changing customer
needs, and which successfully anticipate or respond to changes in technology and
standards on a cost-effective and timely basis. No assurance can be given that
the Company will be able to successfully design or introduce new products in a
timely manner, that the Company will be able to manufacture new products in
volume with acceptable manufacturing yields and gross margins or successfully
market such products, or that such products will perform to specifications on a
long-term basis. In addition, during periods of new product introduction the
Company must manage its inventory more carefully to avoid inventory
obsolescence. The failure of the Company to achieve any of these objectives
could have a material adverse effect on the Company's business and results of
operations.
 
     Until recently, most rigid disc drives used ferrite heads. Although the
performance of ferrite heads has dramatically improved over the years, the need
for higher performance drives and the limitation of ferrite machining technology
led to the development of thin-film heads. Thin-film heads, which are based on
semiconductor processing technology, have better dimensional control than
ferrite heads, permitting a higher density of storage on each disc. Today, all
Seagate drives use thin-film heads. However, the Company believes that as
requirements for even greater storage densities increase, demand for a more
advanced head technology will grow. In anticipation of such growth, the Company
currently has under development magnetoresistive ("MR") heads to be incorporated
into future products. MR heads have discrete read and write structures which
take advantage of special magnetic properties in certain metals to achieve
significantly higher storage capacities. There can be no assurance that the
Company's MR head development effort will be successful and a failure of the
Company to successfully manufacture and market products incorporating MR head
technology in a timely manner could have a material adverse effect on the
Company's business and results of operations. Moreover, International Business
Machines Corporation ("IBM") has initiated a lawsuit against the Company
alleging misappropriation of IBM trade secrets, including trade secrets related
to IBM's MR head
 
                                        4
   5
 
technology. The Company believes that IBM's claims are without merit, is
vigorously defending this suit and is continuing development and preparation for
commercial manufacture of MR heads. However, if IBM prevails in this suit, the
Company could be enjoined from manufacturing MR heads or commercializing disc
drives containing such heads and could also be held liable for damages, any of
which could have a material adverse effect on the Company's business and results
of operations.
 
     Fluctuation of Quarterly Results.  The rigid disc drive industry in which
the Company competes is characterized by variability of demand and declining
unit sales prices over the life of a product, and the Company anticipates that
these characteristics will continue. The Company expects its competitors to
offer new and existing products at prices necessary to gain or retain market
share and customers. This competition and continuing price erosion could
adversely affect the Company's results of operations in any given quarter and
such adverse effect often cannot be anticipated until late in any given quarter.
In addition, the Company's operating results may also be subject to significant
quarterly fluctuations as a result of a number of other factors, including the
timing of orders from and shipment of products to major customers, product mix,
variations in product costs and pricing, delays in product development,
introduction and production, increased competition and general economic and
industry fluctuations.
 
     Variability of Customer Requirements.  The rigid disc drive industry has
been characterized by large volume OEM purchase agreements and large distributor
orders. Typically, the Company's OEM purchase agreements permit customers to
cancel orders and reschedule delivery dates without significant penalties.
Anticipated orders from many of the Company's OEM customers have in the past
failed to materialize or delivery schedules have been deferred as a result of
changes in customer requirements. Such OEM order fluctuations and deferrals have
had a material adverse effect on the Company's results of operations in the
past, and there can be no assurance that the Company will not experience such
adverse effects in the future. Distributors typically furnish the Company with
non-binding indications of their near-term requirements, with product deliveries
based on weekly confirmations. To the extent actual orders from distributors
decrease from their non-binding forecasts, such variances could have a material
adverse effect on the Company's business and results of operations.
 
     Legal Proceedings.  The Company is currently involved in numerous legal
proceedings, including tax proceedings, securities class actions, patent claims,
claims of misappropriation of trade secrets and claims for damages and costs
relating to environmental matters. For a discussion of such legal proceedings
see the "Income Taxes" and "Litigation" footnotes of the Company's consolidated
financial statements incorporated herein by reference. An adverse judgment on
one or more of these legal disputes could have a material adverse effect on the
Company's business and results of operations.
 
     Business Diversification.  In addition to pursuing its core rigid disc
drive business, the Company is broadening its business strategy as a data
technology company to more fully address the markets for storage, retrieval and
management of data. Implementation of this broadened strategy entails risks of
entering markets in which the Company may have limited or no experience. In
addition, such broadened strategy could result in the diversion of management's
attention from the core rigid disc drive business which could adversely impact
the core business. The Company's strategy to sell selected magnetic recording
components to other rigid disc drive manufacturers may improve such
manufacturers' ability to compete with the Company in its core business. The
broadened strategy also entails acquisitions of, or investments in, businesses,
products and technologies. Acquisitions involve numerous risks, including
difficulties in the assimilation of the operations and products of the acquired
businesses and the potential loss of key employees or customers of the acquired
businesses.
 
     High Fixed Costs.  The Company has pursued a strategy of vertical
integration of its manufacturing process in order to reduce unit costs, control
quality and assure availability of certain components. This strategy entails a
high level of fixed costs and requires a high volume of production and sales to
be successful. During periods of decreased production, these high fixed costs
have had, and could in the future have, a material adverse effect on the
Company's business and results of operations.
 
     Manufacturing.  Continued improvement in manufacturing process capabilities
and reduced materials and manufacturing costs will be critical factors affecting
the Company's results of operations. The Company
 
                                        5
   6
 
frequently changes the manufacturing processes for and constituent components of
many of its products and continually evaluates the transfer of volume production
of many of its components and products between facilities. There can be no
assurance that such changes and transfers will be implemented on a timely or
cost-effective basis. Delays or problems encountered in any of the foregoing
could have a material adverse effect on the Company's business and results of
operations.
 
     Competition.  The Company has experienced and expects to continue to
experience intense competition from a number of domestic and foreign companies.
These companies include the other leading independent rigid disc drive
manufacturers, as well as large integrated multinational computer manufactures
such as Digital Equipment Corporation, Fujitsu Limited, Hewlett-Packard Company,
Hitachi Limited, IBM, NEC Corporation and Toshiba Corporation. The Company also
continues to face indirect competition from present and potential customers,
including several of the computer manufacturers listed above, which continuously
evaluate whether to manufacture their own drives or purchase them from outside
sources. The introduction of products using alternative data storage and
retrieval technologies could also be a significant source of competition.
Products based upon such alternative technologies, which include optical
recording technology and semiconductor memory (flash memory, SRAM and DRAM),
could compete with the Company's products in the future.
 
     Availability of Component Supply.  The Company relies on sole sources for
certain components used in some of its products, and has experienced production
delays when unable to obtain sufficient quantities of certain components or
assembly capacity. While the Company maintains component inventory at levels it
believes are adequate for its short-term needs, a prolonged inability to obtain
essential components could have a material adverse effect on the Company's
business and results of operations.
 
     Price Volatility of the Company's Common Stock.  The Company's Common Stock
has historically been subject to substantial price volatility as a result of
quarter-to-quarter variations in the financial results of the Company or its
competitors, announcements of new products by the Company or its competitors and
announcements of changing business conditions by the Company's competitors or
other companies within the computer industry. In addition, the stock market has
experienced and continues to experience extreme price and volume fluctuations
which have particularly affected the market price for many technology companies
and which have often been unrelated to the operating performance of these
companies. These broad market fluctuations, as well as general economic and
political conditions, may adversely affect the market prices of the Company's
Common Stock.
 
                                        6
   7
 
                                USE OF PROCEEDS
 
     The Company will not receive any proceeds from the sale of Common Stock by
the Selling Stockholders.
 
                              SELLING STOCKHOLDERS
 
     The Selling Stockholders are those individuals and entities who will hold
shares of Common Stock issuable upon conversion of the Debentures. As of the
date of this Prospectus, $270,750,000 principal amount of the Debentures is
outstanding. The Debentures are convertible at any time through the close of
business on November 1, 2003, subject to prior redemption, into shares of Common
Stock at a price of $26 1/4 per share, subject to adjustment under certain
circumstances. The registration of the shares of Common Stock offered for resale
hereby is pursuant to a Registration Rights Agreement entered into in connection
with the original issuance of the Debentures (the "Registration Rights
Agreement").
 
     As of the date of this Prospectus, none of the Debentures has been
converted and, as a result, the identity of the Selling Stockholders is not
known. This Prospectus may not be used to consummate sales of Common Stock
unless accompanied by a Prospectus Supplement. The applicable Prospectus
Supplement will set forth the name and number of shares of Common Stock
beneficially owned by each Selling Stockholder selling shares of Common Stock
pursuant to such Prospectus Supplement, the number of shares to be offered by
each Selling Stockholder pursuant to such Prospectus Supplement and the number
of shares to be beneficially owned by each such Selling Stockholder if all of
the shares offered thereby are sold. The applicable Prospectus Supplement will
also indicate whether any Selling Stockholder has held any position or office
with, been employed by, or otherwise had a material relationship with, the
Company or any of its affiliates during the three years prior to the date of
such Prospectus Supplement.
 
                              PLAN OF DISTRIBUTION
 
     The shares of Common Stock to be issued upon conversion of the Debentures
and covered by this Prospectus may be offered and sold from time to time by the
Selling Stockholders. The Selling Stockholders will act independently of the
Company in making decisions with respect to the timing, manner and size of each
sale. Such sales may be made in the over-the-counter market or otherwise, at
market prices prevailing at the time of the sale, at prices related to the then
prevailing market prices or in negotiated transactions, including pursuant to an
underwritten offering or pursuant to one or more of the following methods: (a)
purchases by a broker-dealer as principal and resale by such broker or dealer
for its account pursuant to this Prospectus; (b) ordinary brokerage transactions
and transactions in which a broker solicits purchasers; and (c) block trades in
which a broker-dealer so engaged will attempt to sell the shares as agent but
may take a position and resell a portion of the block as principal to facilitate
the transaction.
 
     In connection with the sale of shares of Common Stock covered hereby,
Selling Stockholders may engage broker-dealers, who in turn may arrange for
other broker-dealers to participate. Broker-dealers may receive commissions or
discounts from the Selling Stockholders in amounts to be negotiated immediately
prior to the sale. In addition, underwriters or agents may receive compensation
from the Selling Stockholders or from purchasers of the shares of Common Stock
covered hereby for whom they may act as agents, in the form of discounts,
concessions or commissions. Underwriters may sell shares of Common Stock to or
through dealers, 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 act as agents. Underwriters, dealers and agents that
participate in the distribution of shares of Common Stock covered hereby may be
deemed to be underwriters, and any discounts or commissions received by them
from the Selling Stockholders and any profit on the resale of shares of Common
Stock by them 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 Selling Stockholders will be described, in
the applicable Prospectus Supplement.
 
     The Registration Rights Agreement provides that the Company will indemnify
the Selling Stockholders against certain liabilities, including liabilities
under the Securities Act.
 
                                        7
   8
 
   
     The Company may suspend the use of this Prospectus for a discrete period of
time if, in the judgment of its Board of Directors, it is advisable to do so due
to pending corporate developments, public filings with the Securities and
Exchange Commission or similar events. The Company is obligated in the event of
such suspension to use its reasonable efforts to ensure that the use of the
Prospectus may be resumed as soon as practicable. This offering will terminate
on the earlier of (a) December 30, 1996 or (b) the date on which all shares
offered hereby have been sold by the Selling Stockholders.
    
 
                                 LEGAL MATTERS
 
     Certain legal matters relating to the validity of the securities offered
hereby will be passed upon for the Company by Wilson, Sonsini, Goodrich and
Rosati, Professional Corporation, Palo Alto, California.
 
                                    EXPERTS
 
     The consolidated financial statements of Seagate Technology, Inc.
incorporated by reference in Seagate Technology, Inc.'s Annual Report (Form
10-K) for the fiscal year ended July 1, 1994 have been audited by Ernst & Young
LLP, independent auditors, as set forth in their report thereon included therein
and incorporated herein by reference. Such consolidated financial statements are
incorporated herein by reference in reliance upon such report given upon the
authority of such firm as experts in accounting and auditing.
 
                                        8
   9
 
             ------------------------------------------------------
             ------------------------------------------------------
 
                               TABLE OF CONTENTS
 


                                        PAGE
                                     
Available Information.................      2
Incorporation of Certain Documents
  by Reference........................      2
The Company...........................      3
Risk Factors..........................      4
Use of Proceeds.......................      7
Selling Stockholders..................      7
Plan of Distribution..................      7
Legal Matters.........................      8
Experts...............................      8
          ------------------------
  NO DEALER, SALESPERSON OR OTHER PERSON HAS
BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO
MAKE ANY REPRESENTATIONS OTHER THAN THOSE
CONTAINED IN THIS PROSPECTUS, AND, IF GIVEN
OR MADE, SUCH INFORMATION AND REPRESENTATIONS
MUST NOT BE RELIED UPON AS HAVING BEEN
AUTHORIZED BY THE COMPANY OR THE SELLING
STOCKHOLDERS. THIS PROSPECTUS DOES NOT
CONSTITUTE AN OFFER TO SELL OR A SOLICITATION
OF AN OFFER TO BUY THE SHARES BY ANYONE IN
ANY JURISDICTION IN WHICH SUCH OFFER OR
SOLICITATION IS NOT AUTHORIZED, OR IN WHICH
THE PERSON MAKING THE OFFER OR SOLICITATION
IS NOT QUALIFIED TO DO SO, OR TO ANY PERSON
TO WHOM IT IS UNLAWFUL TO MAKE SUCH OFFER OR
SOLICITATION. UNDER NO CIRCUMSTANCES SHALL
THE DELIVERY OF THIS PROSPECTUS OR ANY SALE
MADE PURSUANT TO THIS PROSPECTUS, CREATE ANY
IMPLICATION THAT THE INFORMATION CONTAINED IN
THIS PROSPECTUS IS CORRECT AS OF ANY TIME
SUBSEQUENT TO THE DATE OF THIS PROSPECTUS.
 
- ---------------------------------------------
- ---------------------------------------------

 
             ------------------------------------------------------
             ------------------------------------------------------
 
   
                               20,628,572 SHARES
    
 
                            SEAGATE TECHNOLOGY, INC.
 
                                  COMMON STOCK
 
                            ------------------------
 
                                   PROSPECTUS
 
                            ------------------------
 
   
                               SEPTEMBER 19, 1994
    
 
             ------------------------------------------------------
             ------------------------------------------------------