Exhibit 10.1






                               THIRD AMENDMENT TO
                                CREDIT AGREEMENT



                                      AMONG



                              SWIFT ENERGY COMPANY,
                                  AS BORROWER,



                      BANK ONE, TEXAS, NATIONAL ASSOCIATION
                            AS ADMINISTRATIVE AGENT,
                                BANK OF MONTREAL
                            AS SYNDICATION AGENT, AND
                                NATIONSBANK, N.A.
                             AS DOCUMENTATION AGENT



                                       AND



                          THE LENDERS SIGNATORY HERETO




                             Effective July 19, 1999










                                TABLE OF CONTENTS

                                                                       PAGE

ARTICLE I    DEFINITIONS.......................................................1
             1.01  Terms Defined Above.........................................1
             1.02  Terms Defined in Agreement..................................1
             1.03  References..................................................1
             1.04  Articles and Sections.......................................2
             1.05  Number and Gender...........................................2

ARTICLE II   AMENDMENTS........................................................2
             2.01     Amendment of Section 1.2.................................2
             2.02     Amendment of Section 6.20................................3

ARTICLE III  CONDITIONS........................................................3
             3.01     Receipt of Documents.....................................3
             3.02     Accuracy of Representations and Warranties...............3
             3.03     Matters Satisfactory to Lender...........................3

ARTICLE IV   REPRESENTATIONS AND WARRANTIES....................................4

ARTICLE V    RATIFICATION......................................................4

ARTICLE VI   MISCELLANEOUS.....................................................4
             6.01     Scope of Amendment.......................................4
             6.02     Agreement as Amended.....................................4
             6.03     Parties in Interest......................................4
             6.04     Rights of Third Parties..................................4
             6.05     ENTIRE AGREEMENT.........................................4
             6.06     GOVERNING LAW............................................5
             6.07     JURISDICTION AND VENUE...................................5



        THIRD AMENDMENT TO CREDIT AGREEMENT


     This THIRD  AMENDMENT TO CREDIT  AGREEMENT  (this  "Amendment") is made and
entered into effective as of July 19, 1999, by and among SWIFT ENERGY COMPANY, a
Texas  corporation (the  "Borrower"),  each lender that is a signatory hereto or
becomes a signatory  hereto as provided in Section 9.1  (individually,  together
with its successors and assigns, a Lender and, collectively, together with their
respective  successors and assigns, the Lenders),  and BANK ONE, TEXAS, NATIONAL
ASSOCIATION,  a national banking  association,  as Administrative  Agent for the
Lenders  (in such  capacity,  together  with  its  successors  in such  capacity
pursuant to the terms hereof, the  Administrative  Agent),  BANK OF MONTREAL,  a
Canadian chartered bank as Syndication Agent, and NATIONSBANK,  N.A., a national
banking association as Documentation Agent.

                              W I T N E S S E T H:

     WHEREAS,  the above named parties did execute and exchange  counterparts of
that  certain  Credit  Agreement  dated  August  18,  1998,  as amended by First
Amendment to Credit  Agreement  dated September 30, 1998, and as further amended
by  Second   Amendment  to  Credit   Agreement  dated  December  31,  1998  (the
"Agreement"), to which reference is here made for all purposes;

     WHEREAS,  the parties subject to and bound by the Agreement are desirous of
amending the Agreement in the particulars hereinafter set forth;

     NOW, THEREFORE,  in consideration of the mutual covenants and agreements of
the parties to the Agreement, as set forth therein, and the mutual covenants and
agreements  of the parties  hereto,  as set forth in this Third  Amendment,  the
parties hereto agree as follows:

                                   ARTICLE I.
                                   DEFINITIONS

          1.01  Terms  Defined  Above.  As  used  herein,   each  of  the  terms
     "Agreement,"  "Borrower,"  "Amendment," and "Lender" shall have the meaning
     assigned to such term hereinabove.

     1.02 Terms Defined in Agreement.  As used herein,  each term defined in the
Agreement  shall have the  meaning  assigned  thereto in the  Agreement,  unless
expressly provided herein to the contrary.

     1.03  References.  References in this Third Amendment to Article or Section
numbers  shall be to  Articles  and  Sections  of this Third  Amendment,  unless
expressly  stated herein to the contrary.  References in this Third Amendment to
"hereby," "herein," "hereinafter,"  "hereinabove,"  "hereinbelow," "hereof," and
"hereunder" shall be to this Third Amendment in its entirety and not only to the
particular Article or Section in which such reference appears.








     1.04 Articles and Sections. This Third Amendment, for convenience only, has
been divided into  Articles and Sections and it is  understood  that the rights,
powers,  privileges,  duties,  and other legal  relations of the parties  hereto
shall be determined  from this Third Amendment as an entirety and without regard
to such  division  into  Articles and  Sections  and without  regard to headings
prefixed to such Articles and Sections.

     1.05 Number and Gender.  Whenever the context  requires,  reference  herein
made to the single number shall be understood to include the plural and likewise
the plural shall be understood to include the singular. Words denoting sex shall
be  construed  to  include  the  masculine,  feminine,  and  neuter,  when  such
construction  is  appropriate,  and specific  enumeration  shall not exclude the
general,  but shall be construed as cumulative.  Definitions of terms defined in
the singular and plural shall be equally  applicable  to the plural or singular,
as the case may be.


                                   ARTICLE II.
                                   AMENDMENTS

     The Borrower and the Lender  hereby  amend the  Agreement in the  following
particulars:

     2.01  Amendment  of Section  1.2  Section  1.2 of the  Agreement  is hereby
amended in part to read as follows:

     The following definition is amended to read as follows:

     Senior  Subordinated Debt shall mean the Indebtedness of Borrower under the
     Senior Subordinated Notes in the amount up to $150,000,000 due 2009, issued
     or to be issued in accordance  with the terms of the Prospectus  Supplement
     draft dated July 6, 1999, relating thereto.

     2.02  Amendment of Section  6.20.  Section 6.20 of the  Agreement is hereby
amended to read as follows:

     6.20 Senior  Subordinated  Debt. The terms of the Senior  Subordinated Debt
     shall not deviate  materially  from the Prospectus  Supplement  draft dated
     July 6, 1999.










                                  ARTICLE III.
                                   CONDITIONS

     The  obligation of the Lender to amend the Agreement as provided  herein is
subject to the fulfillment of the following conditions precedent:

     3.01 Receipt of Documents.  The Lender shall have received,  reviewed,  and
approved the following  documents and other items,  appropriately  executed when
necessary and in form and substance satisfactory to the Lender:

          (a) multiple counterparts of this Third Amendment, as requested by the
          Lender;

          (b) receipt of executed signature pages from the Required Lenders; and

          (c) such other agreements,  documents,  items, instruments,  opinions,
          certificates,  waivers,  consents,  and  evidence  as the  Lender  may
          reasonably request.

     3.02 Accuracy of Representations  and Warranties.  The  representations and
warranties  contained in Article IV of the  Agreement  and this Third  Amendment
shall be true and correct.

     3.03  Matters   Satisfactory  to  Lender.   All  matters  incident  to  the
consummation of the  transactions  contemplated  hereby shall be satisfactory to
the Lender.


                                   ARTICLE IV.
                         REPRESENTATIONS AND WARRANTIES

     The Borrower hereby expressly re-makes,  in favor of the Lender, all of the
representations  and warranties  set forth in Article IV of the  Agreement,  and
represents and warrants that all such representations and warranties remain true
and unbreached.


                                   ARTICLE V.
                                  RATIFICATION

     Each of the  parties  hereto  does hereby  adopt,  ratify,  and confirm the
Agreement and the other Loan  Documents,  in all things in  accordance  with the
terms and provisions thereof, as amended by this Third Amendment.








                                   ARTICLE VI.
                                  MISCELLANEOUS

     6.01 Scope of  Amendment.  The scope of this Third  Amendment  is expressly
limited to the  matters  addressed  herein and this  Third  Amendment  shall not
operate as a waiver of any past, present, or future breach, Default, or Event of
Default under the Agreement, except to the extent, if any, that any such breach,
Default, or Event of Default is remedied by the effect of this Third Amendment.

     6.02 Agreement as Amended.  All references to the Agreement in any document
heretofore   or  hereafter   executed  in  connection   with  the   transactions
contemplated  in the  Agreement  shall be  deemed to refer to the  Agreement  as
amended by this Third Amendment.

     6.03 Parties in Interest.  All provisions of this Third  Amendment shall be
binding  upon and shall  inure to the  benefit of the  Borrower,  the Lender and
their respective successors and assigns.

     6.04 Rights of Third Parties.  All provisions herein are imposed solely and
exclusively for the benefit of the Lender and the Borrower,  and no other Person
shall have  standing to require  satisfaction  of such  provisions in accordance
with their terms and any or all of such provisions may be freely waived in whole
or in part by the  Lender  at any  time if in its  sole  discretion  it deems it
advisable to do so.

     6.05  ENTIRE  AGREEMENT.   THIS  THIRD  AMENDMENT  CONSTITUTES  THE  ENTIRE
AGREEMENT  BETWEEN THE PARTIES  HERETO  WITH  RESPECT TO THE SUBJECT  HEREOF AND
SUPERSEDES ANY PRIOR  AGREEMENT,  WHETHER WRITTEN OR ORAL,  BETWEEN SUCH PARTIES
REGARDING THE SUBJECT HEREOF.  FURTHERMORE IN THIS REGARD, THIS THIRD AMENDMENT,
THE  AGREEMENT,  THE NOTE,  THE  SECURITY  INSTRUMENTS,  AND THE  OTHER  WRITTEN
DOCUMENTS  REFERRED TO IN THE  AGREEMENT  OR EXECUTED IN  CONNECTION  WITH OR AS
SECURITY FOR THE NOTE  REPRESENT,  COLLECTIVELY,  THE FINAL  AGREEMENT AMONG THE
PARTIES   THERETO   AND  MAY  NOT  BE   CONTRADICTED   BY   EVIDENCE  OF  PRIOR,
CONTEMPORANEOUS,  OR SUBSEQUENT  ORAL  AGREEMENTS  OF THE PARTIES.  THERE ARE NO
UNWRITTEN ORAL AGREEMENTS AMONG THE PARTIES.

     6.06 GOVERNING LAW. THIS THIRD AMENDMENT,  THE AGREEMENT AND THE NOTE SHALL
BE DEEMED TO BE CONTRACTS  MADE UNDER AND SHALL BE CONSTRUED IN ACCORDANCE  WITH
AND  GOVERNED  BY THE LAWS OF THE STATE OF TEXAS.  THE PARTIES  ACKNOWLEDGE  AND
AGREE THAT THIS AGREEMENT AND THE NOTE AND THE TRANSACTIONS  CONTEMPLATED HEREBY
BEAR A NORMAL, REASONABLE, AND SUBSTANTIAL RELATIONSHIP TO THE STATE OF TEXAS.






     6.07  JURISDICTION  AND VENUE.  ALL ACTIONS OR PROCEEDINGS WITH RESPECT TO,
ARISING  DIRECTLY OR INDIRECTLY IN CONNECTION  WITH, OUT OF, RELATED TO, OR FROM
THIS THIRD AMENDMENT,  THE AGREEMENT OR ANY OTHER LOAN DOCUMENT MAY BE LITIGATED
IN COURTS  HAVING SITUS IN HARRIS  COUNTY,  TEXAS.  EACH OF THE BORROWER AND THE
LENDER HEREBY SUBMITS TO THE JURISDICTION OF ANY LOCAL,  STATE, OR FEDERAL COURT
LOCATED IN HARRIS  COUNTY,  TEXAS,  AND HEREBY  WAIVES ANY RIGHTS IT MAY HAVE TO
TRANSFER OR CHANGE THE  JURISDICTION OR VENUE OF ANY LITIGATION  BROUGHT AGAINST
IT BY THE BORROWER OR THE LENDER IN ACCORDANCE WITH THIS SECTION.

     IN WITNESS  WHEREOF,  this Third Amendment to Credit  Agreement is executed
effective the date first hereinabove written.


                                        BORROWER:

                                        SWIFT ENERGY COMPANY



                                        By: /s/ John R. Alden
                                            ------------------------------------
                                            John R. Alden
                                            Senior Vice President


Address for Notices:

Swift Energy Corporation
16825 Northchase Drive, Suite 400
Houston, Texas  77060
Attention:  John R. Alden
Telecopy:  (281) 874-2701








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                                    ADMINISTRATIVE AGENT AND LENDER:

                                    BANK ONE, TEXAS, NATIONAL
                                    ASSOCIATION

                                    By: /s/ Jeff Dalton
                                        ----------------------------------------
                                        Jeff Dalton
                                        Vice President

Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

910 Travis
Houston, Texas 77002

Address for Notices:

Bank One, Texas, National Association
910 Travis
Houston, Texas 77002
Attention: Charles Kingswell-Smith
Telecopy:  (713) 751-3544















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                                       LENDER:

                                       BANK OF MONTREAL

                                       By: /s/ J. R. Whitmore
                                           -------------------------------------
                                           J. R. Whitmore
                                           Director


Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

115 S. LaSalle
11th Floor
Chicago, Illinois 60603
Attention: Charlo Chase


Address for Notices:

Bank of Montreal
700 Louisiana, Suite 4400
Houston, Texas 77002
Attention: Christa Hash
Telecopy:  (713) 223-4007












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                                        LENDER:

                                        BANK OF SCOTLAND

                                        By: /s/ Annie Chin Tat
                                            ------------------------------------
                                            Annie Chin Tat
                                            Senior Vice President



Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

565 Fifth Avenue
New York, New York 10017
Attention: Karen Workman


Address for Notices:
1200 Smith Street
Suite 1750
Houston, Texas 77002
Attention: Richard Butler
Telecopy: 713-651-5714

With a copy to:
Annie Chin Tat
565 Fifth Avenue
New York, New York 10017






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                                          LENDER:

                                          BANK OF AMERICA, N.A. formerly known
                                          as NATIONSBANK, N.A.)

                                          By: /s/ Ronald E. McKaig
                                              ----------------------------------
                                              Ronald E. McKaig
                                              Managing Director

Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

901 Main Street, 14th Floor
Dallas, Texas 70202
Attention: Terri Smith


Address for Notices:
333 Clay Street, Suite 4550
Houston, Texas 77002-4103
Attention: Ron McKaig
Telecopy: 713-651-4888












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                                        LENDER:

                                        THE SANWA BANK, LIMITED

                                        By: /s/ Clyde L. Redford
                                            ------------------------------------
                                            Clyde L. Redford
                                            Vice President



Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

Park Avenue Plaza
55 East 52nd Street
New York, New York 10055
Attention: Wai Mei (Sandy) Lew

Address for Notices:
Park Avenue Plaza
55 East 52nd Street
New York, NY 10055
Attention: Ko Oshima
Telecopy: 212-754-2360

Copy to:

1200 Smith Street, Suite 2670
Houston, Texas 77002
Attention: Clyde Redford
Telecopy: 713-654-1462





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                                         LENDER:

                                         CIBC INC.

                                         By: /s/ Roger Colden
                                             -----------------------------------
                                             Roger Colden
                                             Authorized Signatory



Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

2727 Paces Ferry Road
Suite 1200
2 Paces West, Bldg. 2
Atlanta, Georgia 30339
Attention: Kathryn McGovern
               Senior Associate


Address for Notices:
1600 Smith Street
Suite 3000
Houston, TX 77002
Attention: Mark H. Wolf
Telecopy: 713-650-2588









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                                        LENDER:

                                        FIRST UNION NATIONAL BANK

                                        By: /s/ Paul N. Riddle
                                            ------------------------------------
                                            Senior Vice President



Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

1001 Fannin Street
Suite 2255
Houston, Texas 77002
Attention: Debbie Blank
                  Portfolio Administrator

Address for Notices:
1001 Fannin Street, Suite 2255
Attention: Paul N. Riddle
Telecopy: 713-650-6354














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                                          LENDER:

                                          SOCIETE GENERALE, SOUTHWEST AGENCY

                                          By: /s/ Elizabeth W. Hunter
                                              ----------------------------------
                                              Elizabeth W. Hunter
                                              Director

Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

2001 Ross Avenue, Suite 4800
Dallas, Texas 75201
Attention: Stacie Row


Address for Notices:

1111 Bagby, Suite 2020
Houston, TX 77002
Attention: Elizabeth W. Hunter
Telecopy: 713-650-0824
















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                                          LENDER:

                                          CREDIT LYONNAIS NEW YORK BRANCH

                                          By: /s/ Pascal Poupelle
                                              ----------------------------------
                                              Pascal Poupelle
                                              President and Chief Operating
                                                Officer


Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

1301 Avenue of the Americas, 15th Floor
New York, New York 10019
Attn: Loan Administration Department

with a copy to:

1100 Louisiana, Suite 5360
Houston, Texas 77002
Attention: Bernadette Archie


Address for Notices:

1301 Avenue of the Americas, 15th Floor
New York, New York 10019
Attn: Loan Administration Department

with a copy to:

1000 Louisiana, Suite 5360
Houston, TX 77002
Attention: Jeff Baker
Telecopy: 713-751-0307


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                                           LENDER:

                                           ABN-AMRO BANK N.V.

                                           By: /s/ Jamie A. Conn
                                               ---------------------------------
                                               Jamie A. Conn
                                               Vice President


                                           By: /s/ Stuart Murray
                                               ---------------------------------
                                               Stuart Murray
                                               Vice President


Applicable Lending Office
for Floating Rate Loans and
LIBO Rate Loans:

208 South LaSalle Street, Suite 1500
Chicago, Illinois 60604
Attention: Loan Administration

Address for Notices:
208 South LaSalle Street, Suite 1500
Chicago, Illinois 60604
Attention: Karen MacAllister
Telecopy:   312-904-8840

with copy to:

Three Riverway, Suite 1700
Houston, Texas 77056
Attention: Jamie Conn