EXHIBIT 11

                           MARKWEST HYDROCARBON, INC.
                    COMPUTATION OF EARNINGS PER COMMON SHARE
                         (000S, EXCEPT PER SHARE DATA)



                                                                            FOR THE QUARTER ENDED       FOR THE NINE MONTHS ENDED
                                                                              SEPTEMBER 30, 1998           SEPTEMBER 30, 1998
                                                                          ------------------------    -----------------------------
                                                                                                
Net income                                                                 $       (876)                $       (1,099)
 
Weighted average number of outstanding shares of
     common stock                                                                 8,488                          8,495
 
Basic earnings per share                                                   $      (0.10)                $        (0.13)
                                                                           ============                 ==============
 
Net income                                                                         (876)                        (1,099)
 
Weighted average number of outstanding shares of
     common stock                                                                 8,488                          8,495
Dilutive stock options                                                               69                            119
                                                                           ------------                 --------------
                                                                                  8,557                          8,614
 
Earnings per share assuming dilution                                       $      (0.10)                $        (0.13)
                                                                           ============                 ==============