SCHEDULE 14A INFORMATION
                  Proxy Statement Pursuant to Section 14(a) of
                      the Securities Exchange Act of 1934


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Filed by a Party other than the Registrant   [ ]

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 Rule 14a-11(c) or Rule 14a-12

                                   FILING BY:
                          CYPRUS AMAX MINERALS COMPANY
________________________________________________________________________________
                (Name of Registrant as Specified In Its Charter)

                                      N/A
________________________________________________________________________________
    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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        (2) Aggregate number of securities to which transaction applies:
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            pursuant to Exchange Act Rule 0-11:
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        (4) Date Filed: _______________________________________________________

               As filed with the Commission on September 23, 1999




[Cyprus                                        Cyprus Amax Minerals Company
  Amax     CYPRUS AMAX                         9100 East Mineral Circle
  logo]    MINERALS COMPANY                    Post Office Box 3299
                                               Englewood, Colorado 80155-3299
                                               (303) 643-5000
- --------------------------------------------------------------------------------

[Logo]       CYPRUS AMAX
             MINERALS COMPANY
             ----------------


September 21, 1999

TO:      Participants in the Cyprus Amax Minerals Company Savings Plan and Trust

RE:      Impact of the Proposed Merger on Savings Plan Accounts
         ------------------------------------------------------

         On September 30, 1999, the shareholders of Cyprus Amax Minerals Company
("Cyprus Amax") and ASARCO Incorporated ("Asarco") will vote on the proposed
merger (the "Merger") of Cyprus Amax and Asarco to form Asarco Cyprus
Incorporated ("Asarco Cyprus"). If the shareholders approve the Merger and upon
the completion of the Merger, the shares of Cyprus Amax common stock ("Cyprus
Amax Shares"), if any, held in your account in the Cyprus Amax Minerals Company
Savings Plan and Trust (the "Savings Plan") will need to be adjusted to reflect
the Merger. This memorandum is intended to describe to you the impact that the
Merger will have on your Cyprus Amax Shares held in your account in the Savings
Plan.

         Shares Will Be Exchanged. If the Merger is approved by shareholders and
upon the completion of the Merger, all of the Cyprus Amax Shares in the Savings
Plan will be converted into whole shares of Asarco Cyprus common stock ("Asarco
Cyprus Shares"), pursuant to an exchange ratio established in the merger
agreement between Asarco and Cyprus Amax. Accordingly, each Cyprus Amax Share
will be exchanged for 0.765 of an Asarco Cyprus Share.


================================================================================
Example - Part 1: Assume that Pat is a participant in the Savings Plan and that
Pat's Savings Plan account has been credited with 1,000 Cyprus Amax Shares.
Assume further that the shareholders approve the Merger. As a result, effective
as of the Merger, the 1,000 Cyprus Amax Shares held in Pat's Savings Plan
account will be convened into 765 Asarco Cyprus Shares (that is, 1,000 x 0.765 =
765).
================================================================================


         $5 Special Payment. If the Merger is approved by shareholders and upon
the completion of the Merger, each shareholder of Asarco Cyprus will receive a
special payment of $5 for each Asarco Cyprus Share such shareholder owns (the
"Special Payment"). The Special Payment will be made to shareholders as soon as
possible after the consummation of the Merger.






================================================================================
Example - Part 2: Because Pat's Savings Plan account has been credited with 765
Asarco Cyprus Shares, Pat's account will be allocated with a Special Payment of
$3,825 ($5 x 765 Asarco Cyprus Shares).
================================================================================


         For purposes of the Savings Plan, the Special Payment will be treated
as if it were a dividend payment and will be paid directly into the Savings
Plan. Once contributed to the Savings Plan, the Trustee of the Savings Plan, T.
Rowe Price, will invest the Special Payment that has been allocated to your
Savings Plan account in the available investment funds in the same proportion as
the investment election you have made with respect to your future pre-tax
contributions. If you are not making any future pre-tax contributions, then the
Special Payment will be invested in the same proportion as the investment
election you have made with respect to your future after-tax contributions.


================================================================================
Example - Part 2: Assume that Pat had elected to invest 50% of her future
pre-tax contributions in the Science and Technology Fund and the remaining 50%
in the Cyprus Amax Common Stock fund. As a result, 50% of the Special Payment
allocated to Pat's Savings Plan account will be invested in the Science and
Technology Fund and the remaining 50% will be invested in the Asarco Cyprus
Common Stock fund.
================================================================================


         Future Matching Contributions. If the Merger is approved by the
shareholders and upon the completion of the Merger, then commencing with the
third quarter of 1999, the Company matching contributions made to the Savings
Plan on behalf of any participant who is actively contributing a portion of
his/her base salary under the Savings Plan will be used to purchase Asarco
Cyprus Shares. The current restrictions on a participant's ability to redirect
the investment of matching contributions allocated to such participant's Savings
Plan account will continue to apply.


================================================================================
Example - Part 3: Assume that Pat has elected to contribute 6% of Pat's $25,000
annual base pay as pre-tax contributions to the Savings Plan. At the end of the
third quarter 1999, the Company would make a matching contribution to the
Savings Plan on Pat's behalf equal to $187.50 (that is, $25,000 x 6% x 50% x
1/4). The Trustee would use the $187.50 matching contribution to purchase Asarco
Cyprus Shares on the open market. Assuming solely for purposes of this example,
that the price per Asarco Cyprus Share on the open market at that time is $25,
the Trustee would purchase $187.50 worth of Asarco Cyprus Shares (or 7.5
shares). Thus, 7.5 Asarco Cyprus Shares would be allocated to Pat's Savings Plan
account.
================================================================================


                                      -2-


         IMPORTANT: The assumptions made in this memorandum with respect to the
price per Asarco Cyprus Share is provided solely for illustration purposes and
in no way should be construed as a representation or guarantee of the price of
Asarco Cyprus Shares by the Savings Plan, the Committee, Cyprus Amax, or any
other person.

         If the Merger is not approved by majorities of the shareholders of
Cyprus Amax and Asarco, the above-described changes will not occur. This
memorandum summarizes the material changes to the Savings Plan that would become
effective on the date the Merger is consummated pursuant to the terms of the
agreement between Cyprus Amax and Asarco regarding the Merger. You should keep
this memorandum with your Summary Plan Description for the Savings Plan, which
is located in the "A Summary of Your Benefits" binder, for future reference.

         The Cyprus Amax Minerals Company Benefits Committee (the "Committee"),
as the Savings Plan Administrator, may adopt, from time to time and at any time,
such rules and procedures that it determines to be necessary or desirable with
respect to the operation of the Savings Plan. Cyprus Amax, as the sponsor of the
Savings Plan, and/or the Benefits Committee, within its authority to act on
behalf of Cyprus Amax in a settlor (non-fiduciary) capacity, continue to retain
the right, within its sole discretion and authority, at any time and from time
to time, to amend, modify or eliminate any provision of the Savings Plan and/or
to terminate the Savings Plan.

         Questions? Please direct any questions you may have about this
memorandum or about the Savings Plan in general to your local Organizational
Services representative.



                                               /s/ Chris L. Crowl
                                               ---------------------------
                                               Chris L. Crowl
                                               Director Organizational Services





                                      -3-




[Cyprus                                          Cyprus Amax Minerals Company
 Amax     CYPRUS AMAX                            9100 East Mineral Circle
 logo]    MINERALS COMPANY                       Post Office Box 3299
                                                 Englewood, Colorado 80155-3299
                                                 (303) 643-5000
- --------------------------------------------------------------------------------

September 21, 1999

TO:      Participants in the Cyprus Amax Minerals Company Thrift Plan for
         Bargaining Unit Employees

RE:      Impact of the Proposed Merger on Thrift Plan Accounts

================================================================================

         On September 30, 1999, the shareholders of Cyprus Amax Minerals Company
("Cyprus Amax") and ASARCO Incorporated ("Asarco") will vote on the proposed
merger (the "Merger") of Cyprus Amax and Asarco to form Asarco Cyprus
Incorporated ("Asarco Cyprus"). If the shareholders approve the Merger and upon
the completion of the Merger, the shares of Cyprus Amax common stock ("Cyprus
Amax Shares"), if any, held in your account in the Cyprus Amax Minerals Company
Thrift Plan for Bargaining Unit Employees (the "Thrift Plan") will need to be
adjusted to reflect the Merger. This memorandum is intended to describe to you
the impact that the Merger will have on your Cyprus Amax Shares held in your
account in the Thrift Plan.

         Shares Will Be Exchanged. If the Merger is approved by shareholders and
upon the completion of the Merger, all of the Cyprus Amax Shares in the Thrift
Plan will be converted into whole shares of Asarco Cyprus common stock ("Asarco
Cyprus Shares"), pursuant to an exchange ratio established in the merger
agreement between Asarco and Cyprus Amax. Accordingly, each Cyprus Amax Share
will be exchanged for 0.765 of an Asarco Cyprus Share.


================================================================================
Example - Part 1: Assume that Pat is a participant in the Thrift Plan and that
Pat's Thrift Plan account has been credited with 1,000 Cyprus Amax Shares.
Assume further that the shareholders approve the Merger. As a result, effective
as of the Merger, the 1,000 Cyprus Amax Shares held in Pat's Thrift Plan account
will be converted into 765 Asarco Cyprus Shares (that is, 1,000 x 0.765 = 765).
================================================================================


         $5 Special Payment. If the Merger is approved by shareholders and upon
the completion of the Merger, each shareholder of Asarco Cyprus will receive a
special payment of $5 for each Asarco Cyprus Share such shareholder owns (the
"Special Payment"). The Special Payment will be made to shareholders as soon as
possible after the consummation of the Merger.






================================================================================
Example - Part 2: Because Pat's Thrift Plan account has been credited with 765
Asarco Cyprus Shares, Pat's account will be allocated with a Special Payment of
$3,825 ($5 x 765 Asarco Cyprus Shares).
================================================================================


         For purposes of the Thrift Plan, the Special Payment will be treated as
if it were a dividend payment and will be paid directly into the Thrift Plan.
Once contributed to the Thrift Plan, the Trustee of the Thrift Plan, T. Rowe
Price, will invest the Special Payment that has been allocated to your Thrift
Plan account in the available investment funds in the same proportion as the
investment election you have made with respect to your future pre-tax
contributions. If you are not making any future pre-tax contributions, then the
Special Payment will be invested in the same proportion as the investment
election you have made with respect to your future after-tax contributions.


================================================================================
Example - Part 2: Assume that Pat had elected to invest 50% of her future
pre-tax contributions in the Science and Technology Fund and the remaining 50%
in the Cyprus Amax Common Stock fund. As a result, 50% of the Special Payment
allocated to Pat's Thrift Plan account will be invested in the Science and
Technology Fund and the remaining 50% will be invested in the Asarco Cyprus
Common Stock fund.
================================================================================


         Future Matching Contributions. If the Merger is approved by the
shareholders and upon the completion of the Merger, then commencing with the
third quarter of 1999, the Company matching contributions made to the Thrift
Plan on behalf of any participant who is actively contributing a portion of
his/her base salary under the Thrift Plan will be used to purchase Asarco Cyprus
Shares. The current restrictions on a participant's ability to redirect the
investment of matching contributions allocated to such participant's Thrift Plan
account will continue to apply.


================================================================================
Example - Part 3: Assume that Pat has elected to contribute 6% of Pat's $25,000
annual base pay as pre-tax contributions to the Thrift Plan. At the end of the
third quarter of 1999, the Company would make a matching contribution to the
Thrift Plan on Pat's behalf equal to $187.50 (that is, $25,000 x 6% x 50% x
1/4). The Trustee would use the $187.50 matching contribution to purchase Asarco
Cyprus Shares on the open market. Assuming solely for purposes of this example,
that the price per Asarco Cyprus Share on the open market at that time is $25,
the Trustee would purchase $187.50 worth of Asarco Cyprus Shares (or 7.5
shares). Thus, 7.5 Asarco Cyprus Shares would be allocated to Pat's Thrift Plan
account.
================================================================================


                                      * * *


                                      -2-



         IMPORTANT: The assumptions made in this memorandum with respect to the
price per Asarco Cyprus Share are provided solely for illustration purposes and
in no way should be construed as a representation or guarantee of the price of
Asarco Cyprus Shares by the Thrift Plan, the Committee, Cyprus Amax, or any
other person.

         If the Merger is not approved by majorities of the shareholders of
Cyprus Amax and Asarco, the above-described changes will not occur. This
memorandum summarizes the material changes to the Thrift Plan that would become
effective on the date the Merger is consummated pursuant to the terms of the
agreement between Cyprus Amax and Asarco regarding the Merger. You should keep
this memorandum with your Summary Plan Description for the Thrift Plan, which is
located in the "A Summary of Your Benefits" binder, for future reference.

         The Cyprus Amax Minerals Company Benefits Committee (the "Committee"),
as the Thrift Plan Administrator, may adopt, from time to time and at any time,
such rules and procedures that it determines to be necessary or desirable with
respect to the operation of the Thrift Plan. Cyprus Amax, as the sponsor of the
Thrift Plan, and/or the Benefits Committee, within its authority to act on
behalf of Cyprus Amax in a settlor (non-fiduciary) capacity, continue to retain
the right, within its sole discretion and authority, at any time and from time
to time, to amend, modify or eliminate any provision of the Thrift Plan and/or
to terminate the Thrift Plan.

         Questions? Please direct any questions you may have about this
memorandum or about the Thrift Plan in general to your local Organizational
Services representative.



                                                /s/ Chris L. Crowl
                                                --------------------------------
                                                Chris L. Crowl
                                                Director Organizational Services


                                      -3-