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                            SCHEDULE 14A INFORMATION

          PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

Filed by the Registrant [ ]

Filed by a Party other than the Registrant [X]

Check the appropriate box:

                                            
[ ]  Preliminary Proxy Statement
[ ]  Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
[ ]  Definitive Proxy Statement
[X]  Definitive Additional Materials
[ ]  Soliciting Material Pursuant to sec.240.14a-11(c) or sec.240.14a-12



                          CYPRUS AMAX MINERALS COMPANY
- --------------------------------------------------------------------------------
                (Name of Registrant as Specified In Its Charter)

                            PHELPS DODGE CORPORATION
- --------------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

[X]  No fee required.

[ ]  $125 per Exchange Act Rules O-11(c)(1)(ii), 14a-6(i)(1), 14a-6(i)(2) or
     Item 22(a)(2) of Schedule 14A.

[ ]  Fee computed on table below per Exchange Act Rules 14a-6(i)(4) and 0-11.
     (1)  Title of each class of securities to which transaction applies:

        ------------------------------------------------------------------------

     (2)  Aggregate number of securities to which transaction applies:

        ------------------------------------------------------------------------

     (3)  Per unit price or other underlying value of transaction computed
          pursuant to Exchange Act Rule 0-11 (set forth the amount on which the
          filing fee is calculated and state how it was determined):

        ------------------------------------------------------------------------

     (4)  Proposed maximum aggregate value of transaction:

        ------------------------------------------------------------------------

     (5)  Total fee paid:

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[ ]  Fee paid previously by written preliminary materials.

[ ]  Check box if any part of the fee is offset as provided by Exchange Act Rule
     0-11(a)(2) and identify the filing for which the offsetting fee was paid
     previously. Identify the previous filing by registration statement number,
     or the Form or Schedule and the date of its filing.

     (1)  Amount Previously Paid:

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     (2)  Form, Schedule or Registration Statement No.:

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     (3)  Filing Party:

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     (4)  Date Filed:

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NOTES:
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                        [PHELPS DODGE CORPORATION LOGO]

September 11, 1999

Dear Cyprus Amax Shareholder:

                             WELCOME BACK TO VALUE

While many of you were on vacation, Asarco and Cyprus Amax repeatedly refused to
meet with Phelps Dodge and unilaterally rejected our acquisition proposals
offering you a substantial premium for your shares. Instead they endorsed the
no-premium Asarco/Cyprus Amax merger proposal which will be voted on at hastily
called September 30 shareholder meetings.

Don't be confused by the rhetoric surrounding the Asarco and Cyprus Amax merger
vote. Protect your investment by signing, dating and returning the enclosed GOLD
proxy card today.

Your vote will determine the future of your investment. In making your decision,
you should compare Phelps Dodge's solid record of performance with the
lackluster records of Asarco and Cyprus Amax. WHICH STOCK WOULD YOU RATHER OWN?

                            PERFORMANCE VS. PROMISES

                          [GRAPHICAL DISPLAY OMITTED]
This graph displays the total return on the common stock of Phelps Dodge
(1024%), Cyprus Amax (102%) and Asarco (25%) over the past 15 years using a base
date of August 10, 1984.
Source: Morgan Stanley Dean Witter  Note: Cyprus Amax returns measured from 5/85
IPO
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As illustrated above, if you had invested one hundred dollars in Phelps Dodge 15
years ago, you would have earned a total return of more than $1,000, compared to
only $102 for a similar investment in Cyprus Amax(1) or a paltry $25 for Asarco.
DO YOU WANT PHELPS DODGE'S PROVEN PERFORMANCE -- OR MORE PROMISES FROM ASARCO
AND CYPRUS AMAX?

The choice is clear. Don't forfeit your opportunity to obtain maximum value for
your shares. You can say yes to value by signing, dating and returning the
enclosed GOLD proxy card today.

Very truly yours,


/s/ Douglas C. Yearley                     /s/ J. Steven Whisler
Douglas C. Yearley                         J. Steven Whisler
Chairman and Chief Executive Officer       President and Chief Operating Officer

      IF YOU HAVE ANY QUESTIONS OR NEED ASSISTANCE IN VOTING YOUR SHARES,
       PLEASE CALL INNISFREE M&A INCORPORATED TOLL FREE AT 877-750-5838.

        If you have already returned a WHITE proxy card to Cyprus Amax,
                   you have every right to change your vote.
                Please sign and date the GOLD proxy card today.
                      Only your latest dated proxy counts.

(1) Cyprus Amax returns measured from 5/85 IPO

    This letter is neither an offer to exchange nor a solicitation of an offer
to exchange the common stock of Asarco or Cyprus Amax for common stock of Phelps
Dodge. The offers will be made solely by means of Phelps Dodge's Prospectus and
the related Letter of Transmittal. This letter shall not constitute an offer to
sell or the solicitation of an offer to buy nor shall there be any sale of these
securities in any state in which such offer, solicitation or sale would be
unlawful prior to registration or qualification under the securities laws of any
such state.