EXHIBIT 99(a)


            COEUR D'ALENE MINES CORPORATION AND ASARCO INCORPORATED
                           COMBINE SILVER INTERESTS


      COEUR D'ALENE,  IDAHO, MAY 13, 1999 - ASARCO Incorporated  (NYSE:AR) and
Coeur  d'Alene Mines  Corporation  (NYSE:CDE)  announced  today that they have
agreed to a  transaction  in which Asarco will acquire a fully  diluted  19.3%
common stock  interest in Coeur d'Alene Mines in exchange for most of Asarco's
silver mining assets. Asarco will also nominate two directors to Coeur d'Alene
Mines' Board of  Directors.  Asarco and Coeur d'Alene Mines have had a 52-year
relationship  principally  involving  the  operation  of the Coeur and  Galena
silver mines in Idaho.

      Asarco will acquire  7.125  million  newly issued common shares of Coeur
d'Alene Mines.  In exchange for this interest,  Asarco will contribute its 50%
interest in Silver Valley Resources Corporation,  which operates the Coeur and
Galena silver mines; Asarco's wholly-owned subsidiary, Empress Minera Manquiri
S.R.L.,  which owns an  advanced  Bolivian  silver  exploration  project;  1.5
million  shares and warrants,  representing  an approximate 5% interest in Pan
American Silver Corporation (NASDAQ: PAAS US) of Vancouver,  British Columbia;
and a 20% net profits interest in the Quiruvilca  silver mine in Peru operated
by Pan American Silver.

      The transaction  represents the latest restructuring of Asarco and Coeur
d'Alene Mines' joint mining interests in Idaho. The Galena mine, near Wallace,
Idaho, was developed by Asarco under terms of a lease from Coeur d'Alene Mines
and its  predecessor  companies  originally  executed in 1947. The Coeur mine,
also near Wallace,  was developed by Asarco under a joint agreement with Coeur
d'Alene Mines entered into in 1964.




      In October  1994,  Asarco  and Coeur  d'Alene  Mines  agreed to form the
jointly owned Silver Valley Resources Corporation, which now owns and operates
both the Galena and Coeur mines.  After this transaction,  Coeur d'Alene Mines
will own 100% of Silver Valley Resources.

      Commenting on the transaction, Francis R. McAllister, Chairman and Chief
Executive   Officer  of  Asarco,   said:  "Coeur  d'Alene  Mines  has  been  a
constructive  and  valued  partner  in our  Idaho  mining  ventures.  The  new
structure created by this transaction offers both companies the opportunity to
pursue our long-standing  interests in silver mining in Idaho and elsewhere in
a cooperative and cost-effective way."

      "For Asarco,  the  transaction  deepens our historic  interest in Idaho,
giving  us  significant  representation  on the Board of  Directors  of one of
Idaho's  leading  mining  companies  with a broad  portfolio of precious metal
mining opportunities."

      Commenting on the proposed transaction,  Dennis E. Wheeler, Chairman and
Chief Executive Officer of Coeur d'Alene Mines said: "The acquisition of these
fine  silver  assets from Asarco  represents  Coeur's  first major step in its
strategy to focus on expanding its leading  position as the country's  largest
primary silver  producer.  This  transaction  allows Coeur to bring additional
synergies  to the  development  of  Silver  Valley  Resources  because  of the
proximity of our corporate headquarters to the Silver Valley. This transaction
also gives  Coeur a major  advanced-stage  silver  project  in Bolivia  with a
resource  base the size of our  leading  Rochester  mine and an  interest in a
Canadian silver mining company in a geographic area where we have no presence.
We are very  pleased  that  Asarco  has chosen to express  its  confidence  by
becoming a major  shareholder  in Coeur  d'Alene  Mines,  further  extending a
relationship which began so many years ago."


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      The proposed  transaction is subject to approval by Coeur d'Alene Mines'
shareholders   and  any  necessary   clearance  under  the   Hart-Scott-Rodino
Anti-Trust Improvements Act.

      ASARCO  Incorporated is one of the world's leading integrated  producers
of copper, as well as a producer of specialty chemicals,  aggregates and other
metals.

      Coeur d'Alene Mines Corporation is one of North America's leading silver
producers and an international gold producer.


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