<ARTICLE> 5
<MULTIPLIER> 1,000,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-END>                               MAR-31-1998
<CASH>                                             487
<SECURITIES>                                         0
<RECEIVABLES>                                     1845
<ALLOWANCES>                                        19
<INVENTORY>                                       2359
<CURRENT-ASSETS>                                  5073
<PP&E>                                           27161
<DEPRECIATION>                                   15660
<TOTAL-ASSETS>                                   20342
<CURRENT-LIABILITIES>                             4298
<BONDS>                                           3313
<PREFERRED-MANDATORY>                              182
<PREFERRED>                                          3
<COMMON>                                           376<F1>
<OTHER-SE>                                        5216
<TOTAL-LIABILITY-AND-EQUITY>                     20342
<SALES>                                           6887
<TOTAL-REVENUES>                                  7187
<CGS>                                             6623
<TOTAL-COSTS>                                     6623
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                  89
<INCOME-PRETAX>                                    482
<INCOME-TAX>                                       158
<INCOME-CONTINUING>                                270
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                       270
<EPS-PRIMARY>                                        0<F2>
<EPS-DILUTED>                                        0<F3>
<FN>
<F1>Consists of Marathon Stock issued, $289; Steel Stock issued, $87.
<F2>Basic earnings per share applicable to Marathon Stock,$.63; Steel Stock,
 $.98.
<F3>Diluted earnings per share applicable to Marathon Stock, $.63; Steel Stock,
$.95.
</FN>