<ARTICLE> 5 <MULTIPLIER> 1,000 <PERIOD-TYPE> 3-MOS <FISCAL-YEAR-END> DEC-31-1998 <PERIOD-START> JAN-01-1998 <PERIOD-END> MAR-31-1998 <CASH> 128,930 <SECURITIES> 328,828 <RECEIVABLES> 230,584 <ALLOWANCES> 2,325 <INVENTORY> 100,390 <CURRENT-ASSETS> 851,456 <PP&E> 1,792,520 <DEPRECIATION> 648,701 <TOTAL-ASSETS> 2,132,221 <CURRENT-LIABILITIES> 410,564 <BONDS> 0 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 1,403 <OTHER-SE> 1,597,097 <TOTAL-LIABILITY-AND-EQUITY> 2,132,221 <SALES> 324,850 <TOTAL-REVENUES> 324,850 <CGS> 183,106 <TOTAL-COSTS> 183,106 <OTHER-EXPENSES> 108,980 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 0 <INCOME-PRETAX> 40,610 <INCOME-TAX> 10,167 <INCOME-CONTINUING> 30,443 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 30,443 <EPS-PRIMARY> 0.22 <EPS-DILUTED> 0.22