EXHIBIT 10.1

                       THIRD AMENDMENT OF CREDIT AGREEMENT

         THIS THIRD AMENDMENT OF CREDIT AGREEMENT (this  "Amendment"),  dated as
of May 12, 1999, is by and between COLUMBUS ENERGY CORP., a Colorado corporation
(herein called "Borrower"),  and NORWEST BANK COLORADO,  NATIONAL ASSOCIATION, a
national banking association (herein called "Norwest").

                                    RECITALS

         A.  Borrower and Norwest  entered  into an Amended and Restated  Credit
Agreement  dated as of October 23, 1996,  as amended by  amendments  dated as of
September 8, 1998 and October 6, 1998 (the "Credit Agreement"),  in order to set
forth the terms upon which  Norwest  would make  available to Borrower a line of
credit and by which the line of credit would be governed. Capitalized terms used
herein  without  definition  shall  have the same  meanings  as set forth in the
Credit Agreement.

         B.  Borrower and Norwest wish to enter into this  Amendment in order to
amend further certain terms and provisions of the Credit Agreement.

                                    AGREEMENT

         NOW, THEREFORE,  in consideration of $10.00 and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

         1.  Credit  Agreement.  The Credit  Agreement  shall be, and hereby is,
amended as follows as of the date hereof:

                         (a)  The  following   shall  be  substituted   for  the
definition of "Borrowing Base Period" in Section 1.1 on page
2 of the Credit Agreement:

                         "Borrowing Base Period" means:  (a) the period from the
                    date  of  this   Agreement   through  March  31,  1997;  (b)
                    thereafter,  until April 1, 2001, each  twelve-month  period
                    beginning  on April 1 of each year;  and (c) the period from
                    April 1, 2001 to July 1, 2001.

                         (b)  The   following  shall  be  substituted  for   the
definition of "Maturity Date" in Section 1.1 on page 7 of the Credit Agreement:

                          "Maturity Date" means July 1, 2005.


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                         (c)  The  following   shall  be  substituted   for  the
definition of "Principal Payment Date" in Section 1.1 on page
8 of the Credit Agreement:

                         "Principal  Payment Date" means: (a) the first Business
                    Day of each calendar month,  commencing  August 1, 2001, and
                    (b) if all  Obligations due and payable on any such date are
                    not then paid, each succeeding day until all due and payable
                    Obligations are paid in full.

                         (d)  The   following  shall  be  substituted  for   the
definition  of  "Revolving  Period"  in  Section  1.1 on  page 8  of the  Credit
Agreement:

                          "Revolving Period" means the time period from the date
                     of this Agreement to July 1, 2001.

         2. The Note.  The Note shall be amended,  such amendment to be effected
by an Allonge (the "Allonge") to be attached to the Note and to be substantially
in the form of Exhibit A attached hereto and made a part hereof.

         3.  Loan  Documents.  All  references  in any  document  to the  Credit
Agreement  and the Note shall  refer to the Credit  Agreement  and the Note,  as
amended pursuant to this Amendment and the Allonge.

         4. Conditions Precedent. The obligations of the parties under
this  Amendment and under the foregoing  amendments to the Credit  Agreement and
the Note are subject, at the option of Norwest, to the prior satisfaction of the
condition  that  Borrower  shall have  executed  and  delivered  to Norwest  the
following (all documents to be satisfactory in form and substance to Norwest):

                         (a)      This Amendment.

                         (b)      The Allonge.

                         (c) A Consent of Guarantor executed by CGSI in the form
of Exhibit B attached hereto and made a part
hereof.

         5. Representations and Warranties. Borrower hereby certifies to Norwest
that as of the date of this Amendment: (a) all of Borrower's representations and
warranties  contained in the Credit Agreement are true, accurate and complete in
all material  respects,  and (b) no Default or Event of Default has occurred and
is continuing under the Credit Agreement.

                                       2
<PAGE>


         6.  Continuation of the Credit  Agreement.  Except as specified in this
Amendment and the Allonge,  the provisions of the Credit  Agreement and the Note
shall  remain in full force and effect,  and if there is a conflict  between the
terms of this Amendment or the Allonge and those of the Credit  Agreement or the
Note, the terms of this Amendment and the Allonge shall control.

         7.  Expenses.  Borrower  shall pay all expenses  incurred in connection
with  the  transactions  contemplated  by  this  Amendment,   including  without
limitation all fees and expenses of Norwest's attorney.

         8.  Miscellaneous.  This  Amendment  shall be governed by and construed
under the laws of the State of Colorado  and shall be binding  upon and inure to
the  benefit  of the  parties  hereto and their  successors  and  assigns.  This
Amendment may be executed in any number of counterparts,  each of which shall be
an original, but all of which together shall constitute one instrument.

                Executed as of the date first above written.

                                COLUMBUS ENERGY CORP.


                            By: /s/ Michael M. Logan
                                ---------------------
                                Michael M. Logan,
                                Vice President

                               NORWEST BANK COLORADO, NATIONAL ASSOCIATION


                            By: /s/ J. Thomas Reagan
                                --------------------
                                J. Thomas Reagan,
                                Vice President

                                       3
<PAGE>

                                    EXHIBIT A

                                     ALLONGE

                FOR  VALUE   RECEIVED,   COLUMBUS   ENERGY  CORP.,   a  Colorado
corporation  ("Columbus"),  and NORWEST BANK COLORADO,  NATIONAL ASSOCIATION,  a
national banking association  ("Norwest"),  hereby agree to amend the Promissory
Note dated July 1, 1992, as previously amended (the "Note"),  in the face amount
of $10,000,000, made by Columbus, payable to the order of Norwest, as follows:

                1.  By substituting the following for the first  sentence of the
third paragraph on page 1 of the Note:

                  The outstanding principal amount of this Note shall be payable
                  as provided in the Credit Agreement,  in monthly  installments
                  due  on  the  first  Business  Day  of  each  calendar  month,
                  commencing  August 1,  2001,  as more fully  described  in the
                  Credit Agreement.

                2.  By substituting the following for the third sentence  of the
 third paragraph on page 1 of the Note:

                  The entire outstanding principal balance of this Note shall be
                  due and  payable  on  July  1,  2005  (unless  payable  sooner
                  pursuant to the terms of the Credit Agreement).

                3.  By substituting the following for the first sentence  of the
 fifth paragraph on page 1 of the Note:

                  Interest  on Prime  Rate  Advances  shall  be due and  payable
                  monthly on the first Business Day of each calendar month, from
                  the date hereof through July 1, 2005.

                4.  By substituting the following for the third sentence  of the
fifth paragraph on page 1 of the Note:

                  All  accrued and unpaid  interest  will be due and payable not
later than July 1, 2005.

                DATED as of May 12, 1999.

                                COLUMBUS ENERGY CORP.

                         By: __________________________
                                 Michael M. Logan,
                                 Vice President


                                      A-1

<PAGE>


                             NORWEST BANK COLORADO, NATIONAL  ASSOCIATION


                         By: __________________________
                                J. Thomas Reagan,
                                Vice President















                                      A-2
<PAGE>

                                    EXHIBIT B


                              CONSENT OF GUARANTOR

                For good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged,  Columbus Gas Services, Inc. ("Guarantor"), as
the  Guarantor  under a Guaranty  Agreement  dated July 1, 1992, as amended (the
"Guaranty"),  given by Guarantor to Norwest Bank Colorado,  National Association
(the  "Bank"),   to  guaranty  certain  obligations  of  Columbus  Energy  Corp.
("Borrower"), to the Bank, hereby consents to, and agrees with the Bank that the
Amended  and  Restated  Credit  Agreement  dated  as of  October  23,  1996,  as
previously  amended (the  "Credit  Agreement"),  between  Borrower and the Bank,
shall be amended  pursuant to a Third Amendment of Credit  Agreement dated as of
May 12, 1999,  between Borrower and the Bank,  including without  limitation the
extension  of the  end of the  "Revolving  Period"  (as  defined  in the  Credit
Agreement) to July 1, 2001 and the extension of the "Maturity  Date" (as defined
in the Credit Agreement) to July 1, 2005.

                Guarantor  hereby  ratifies  and adopts the  Guaranty and agrees
that the Guaranty shall cover any and all  indebtedness,  whether for principal,
interest,  fees or other  amounts,  incurred by Borrower to the Bank pursuant to
the Amended and Restated Credit Agreement.

                Dated as of May 12, 1999.


                           COLUMBUS GAS SERVICES, INC.


                         By: __________________________
                                Michael M. Logan,
                                Executive Vice President








                                      B-1
<PAGE>

                                     ALLONGE

                FOR  VALUE   RECEIVED,   COLUMBUS   ENERGY  CORP.,   a  Colorado
corporation  ("Columbus"),  and NORWEST BANK COLORADO,  NATIONAL ASSOCIATION,  a
national banking association  ("Norwest"),  hereby agree to amend the Promissory
Note dated July 1, 1992, as previously amended (the "Note"),  in the face amount
of $10,000,000, made by Columbus, payable to the order of Norwest, as follows:

                1.  By substituting the following for the first sentence  of the
third paragraph on page 1 of the Note:

                  The outstanding principal amount of this Note shall be payable
                  as provided in the Credit Agreement,  in monthly  installments
                  due  on  the  first  Business  Day  of  each  calendar  month,
                  commencing  August 1,  2001,  as more fully  described  in the
                  Credit Agreement.

                2.  By substituting the following for the third sentence  of the
third paragraph on page 1 of the Note:

                  The entire outstanding principal balance of this Note shall be
                  due and  payable  on  July  1,  2005  (unless  payable  sooner
                  pursuant to the terms of the Credit Agreement).

                3.  By substituting the following for the first  sentence of the
fifth paragraph on page 1 of the Note:

                  Interest  on Prime  Rate  Advances  shall  be due and  payable
                  monthly on the first Business Day of each calendar month, from
                  the date hereof through July 1, 2005.

                4.  By substituting the following for the third sentence  of the
fifth paragraph on page 1 of the Note:

                  All  accrued and unpaid  interest  will be due and payable not
later than July 1, 2005.

                DATED as of May 12, 1999.

                                                   COLUMBUS ENERGY CORP.


                                               By: /s/ Michael M. Logan
                                                   ----------------------
                                                   Michael M. Logan,
                                                   Vice President



<PAGE>





                                                   NORWEST BANK COLORADO,
                                                       NATIONAL  ASSOCIATION


                                               By: /s/ J. Thomas Reagan
                                                   ----------------------
                                                   J. Thomas Reagan,
                                                   Vice President




















                                       2
<PAGE>

                              CONSENT OF GUARANTOR

                For good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged,  Columbus Gas Services, Inc. ("Guarantor"), as
the  Guarantor  under a Guaranty  Agreement  dated July 1, 1992, as amended (the
"Guaranty"),  given by Guarantor to Norwest Bank Colorado,  National Association
(the  "Bank"),   to  guaranty  certain  obligations  of  Columbus  Energy  Corp.
("Borrower"), to the Bank, hereby consents to, and agrees with the Bank that the
Amended  and  Restated  Credit  Agreement  dated  as of  October  23,  1996,  as
previously  amended (the  "Credit  Agreement"),  between  Borrower and the Bank,
shall be amended  pursuant to a Third Amendment of Credit  Agreement dated as of
May 12, 1999,  between Borrower and the Bank,  including without  limitation the
extension  of the  end of the  "Revolving  Period"  (as  defined  in the  Credit
Agreement) to July 1, 2001 and the extension of the "Maturity  Date" (as defined
in the Credit Agreement) to July 1, 2005.

                Guarantor  hereby  ratifies  and adopts the  Guaranty and agrees
that the Guaranty shall cover any and all  indebtedness,  whether for principal,
interest,  fees or other  amounts,  incurred by Borrower to the Bank pursuant to
the Amended and Restated Credit Agreement.

                Dated as of May 12, 1999.


                                                COLUMBUS GAS SERVICES, INC.


                                            By: /s/ Michael M. Logan
                                                --------------------------
                                                Michael M. Logan,
                                                Executive Vice President