<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
UNAUDITED FINANCIAL STATEMENT OF ATLAS-ENERGY FOR THE NINETIES-PUBLIC #6 LTD.
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                                                  
<PERIOD-TYPE>                   3-MOS                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999             DEC-31-1999
<PERIOD-START>                             JUN-30-2000             DEC-31-1999
<PERIOD-END>                               SEP-30-2000             SEP-30-2000
<CASH>                                          22,623                  22,623
<SECURITIES>                                         0                       0
<RECEIVABLES>                                  319,165                 319,165
<ALLOWANCES>                                         0                       0
<INVENTORY>                                          0                       0
<CURRENT-ASSETS>                               341,788                 341,788
<PP&E>                                      10,355,659              10,355,659
<DEPRECIATION>                             (2,932,175)             (2,932,175)
<TOTAL-ASSETS>                               7,765,272               7,765,272
<CURRENT-LIABILITIES>                           15,230                  15,230
<BONDS>                                              0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                             0                       0
<OTHER-SE>                                   7,750,042               7,750,042
<TOTAL-LIABILITY-AND-EQUITY>                 7,765,272               7,765,272
<SALES>                                        418,000               1,181,156
<TOTAL-REVENUES>                               425,332               1,195,589
<CGS>                                           52,266                 147,154
<TOTAL-COSTS>                                   52,266                 147,155
<OTHER-EXPENSES>                               245,550                 765,805
<LOSS-PROVISION>                                     0                       0
<INTEREST-EXPENSE>                                   0                       0
<INCOME-PRETAX>                                127,516                 282,630
<INCOME-TAX>                                         0                       0
<INCOME-CONTINUING>                            127,516                 282,630
<DISCONTINUED>                                       0                       0
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                   127,516                 282,630
<EPS-BASIC>                                          0                       0
<EPS-DILUTED>                                        0                       0