EXHIBIT 4


                    AMENDMENT NO. 1 TO RIGHTS AGREEMENT

     THIS AMENDMENT NO. 1 (the "Amendment")  dated as of March 18, 2004, to
the Rights  Agreement,  dated as of May 16, 1996 (the "Rights  Agreement"),
between Ashland Inc., a Kentucky corporation (the "Company"),  and National
City Bank, a Delaware corporation, as successor to Harris Trust and Savings
Bank by  appointment,  as Rights  Agent (the  "Rights  Agent").  Terms used
herein  and not  otherwise  defined  shall  have  the  respective  meanings
ascribed to such terms in the Rights Agreement.

     WHEREAS  the  Company,  ATB  Holdings  Inc.,  a  Delaware  corporation
("HoldCo"),  EXM LLC, a Kentucky  limited  liability  company ("New Ashland
LLC"), New EXM Inc., a Kentucky corporation ("New Ashland Inc."),  Marathon
Oil Corporation, a Delaware corporation ("Marathon"), Marathon Oil Company,
an Ohio corporation ("Marathon Company"), Marathon Domestic LLC, a Delaware
limited  liability  company ("Merger Sub"), and Marathon Ashland  Petroleum
LLC, a Delaware limited liability  company ("MAP"),  have proposed to enter
into  a  Master  Agreement  to  be  dated  the  date  hereof  (the  "Master
Agreement");

     WHEREAS the Company  desires to amend the Rights  Agreement  to render
the  Rights  inapplicable  to the  Transactions  (as  defined in the Master
Agreement)  contemplated by the Master Agreement and the other  Transaction
Agreements (as defined in the Master Agreement);

     WHEREAS the Company desires that, at the Acquisition  Merger Effective
Time (as  defined in the  Master  Agreement),  (A) New  Ashland  Inc.  will
succeed to all the rights and  obligations  of the Company under the Rights
Agreement;  (B) all references to Common Stock of the Company and Preferred
Shares of the Company  will be deemed to be  references  to Common Stock of
New Ashland  Inc. and  Preferred  Shares of New Ashland  Inc.;  and (C) the
Rights Agreement will continue in effect;

     WHEREAS the Company deems this Amendment to the Rights Agreement to be
desirable  and in the best  interests  of the holders of the Rights and has
duly approved this Amendment; and

     WHEREAS Section 26 of the Rights Agreement  permits the Company at any
time before the  occurrence  of a  Distribution  Date and before any person
becomes an  Acquiring  Person to amend the Rights  Agreement  in the manner
provided herein.

     NOW THEREFORE, the parties hereby agree as follows:

     1. Succession and  Continuance.  Effective at the  Acquisition  Merger
Effective  Time,  New  Ashland  Inc.  will  succeed  to all the  rights and
obligations  of the  Company  under the  Rights  Agreement  and the  Rights
Agreement will continue in effect after the  Acquisition  Merger  Effective
Time.

     2.  Substitution  of New Ashland  Inc.  Effective  at the  Acquisition
Merger  Effective  Time,  all references to Common Stock of the Company and
Preferred  Shares of the Company in the Rights  Agreement will be deemed to
be references  to Common Stock of New Ashland Inc. and Preferred  Shares of
New Ashland Inc.

     3.  Amendment  of Section  1.  Section 1 of the  Rights  Agreement  is
supplemented to add the following definitions in the appropriate locations:

     "HOLDCO"  means ATB Holdings Inc., a Delaware  corporation  and wholly
owned subsidiary of the Company.

     "MASTER AGREEMENT" shall mean the Master Agreement,  dated as of March
18, 2004,  among the Company,  HoldCo,  New Ashland LLC, New Ashland  Inc.,
Marathon,  Marathon Company, Merger Sub, and MAP, as it may be amended from
time to time.

     "MERGER SUB" means Marathon Domestic LLC, a Delaware limited liability
company and wholly owned subsidiary of Marathon.

     "MARATHON" means Marathon Oil Corporation, a Delaware corporation.

     "MARATHON COMPANY" means Marathon Oil Company, an Ohio corporation and
wholly owned subsidiary of Marathon.

     "MAP"  means  Marathon  Ashland  Petroleum  LLC,  a  Delaware  limited
liability company owned by Marathon Company and the Company.

     "NEW  ASHLAND  INC." means New EXM Inc.,  a Kentucky  corporation  and
wholly owned subsidiary of HoldCo.

     "NEW ASHLAND LLC" means EXM LLC, a Kentucky limited  liability company
and wholly owned subsidiary of HoldCo.

     4. Amendment of the Definition of "Acquiring  Person".  The definition
of  "ACQUIRING  PERSON" in Section 1 of the Rights  Agreement is amended by
adding the following sentence at the end thereof:

     "Notwithstanding  anything in this Rights  Agreement to the  contrary,
none of Marathon,  Marathon Company,  Merger Sub, MAP, HoldCo,  New Ashland
LLC, New Ashland Inc. or any other Person,  individually,  or collectively,
shall be  deemed  to be an  Acquiring  Person  solely  by virtue of (i) the
execution  and delivery of the Master  Agreement  or any other  Transaction
Agreement (as defined in the Master  Agreement) or (ii) the consummation of
the Transactions (as defined in the Master Agreement)."

     5.  Amendment of Section 3.  Section  3(b) of the Rights  Agreement is
amended  and  supplemented  by adding  the  following  sentence  at the end
thereof:

     "Notwithstanding  anything in this Rights Agreement to the contrary, a
Distribution  Date or  Business  Combination  shall  not be  deemed to have
occurred,  no Rights  shall  separate  from the Common  Shares or otherwise
become exerciseable and no adjustment shall be made pursuant to Sections 11
or 12, in each case solely as a result of (i) the execution and delivery of
the Master Agreement or any other Transaction  Agreement (as defined in the
Master  Agreement) or (ii) the consummation of the Transactions (as defined
in the Master Agreement)."

     Furthermore,  Section 3 of the Rights  Agreement is amended to add the
following sentence at the end thereof as Section 3(e):

     "Nothing  in this  Rights  Agreement  shall be  construed  to give any
holder  of  Rights  or any other  Person  any  legal or  equitable  rights,
remedies or claims under this Rights  Agreement by virtue of the  execution
and delivery of the Master Agreement or any other Transaction Agreement (as
defined in the Master  Agreement),  or by virtue of any of the Transactions
(as defined in the Master  Agreement),  including  without  limitation  the
consummation thereof."

     6.  Effectiveness.  This Amendment shall be deemed effective as of the
date first written  above,  as if executed on such date.  Except as amended
hereby,  the  Rights  Agreement  shall  remain in full force and effect and
shall be otherwise unaffected hereby.

     7.  Miscellaneous.  This  Amendment  may be  executed  in one or  more
counterparts,  all of which shall be considered  one and the same agreement
and shall  become  effective  immediately  upon  execution  by the Company,
whether or not also executed by the Rights Agent.  This Amendment  shall be
deemed to be a contract made under the laws of the Commonwealth of Kentucky
and for all purposes shall be governed by and construed in accordance  with
the laws of such State  applicable  to contracts  to be made and  performed
entirely within such State. If any term, provision, covenant or restriction
of this  Amendment  is held by a court of competent  jurisdiction  or other
authority to be invalid, void or unenforceable, the remainder of the terms,
provisions,  covenants and  restrictions  of this Amendment shall remain in
full  force  and  effect  and  shall  in no way be  affected,  impaired  or
invalidated.  The  Rights  Agent and the  Company  hereby  waive any notice
requirement under the Rights Agreement pertaining to the matters covered by
this Amendment.




     IN WITNESS  WHEREOF,  the parties hereto have caused this Amendment to
be executed and delivered by their authorized officers as of the date first
written above.



                                        ASHLAND INC.,

                                        by /s/ James J. O'Brien
                                        ------------------------
                                        Name:  James J. O'Brien
                                        Title: Chief Executive
                                               Officer


                                        National City Bank,

                                        by /s/ Marlayna J. Jeanclerc
                                        ----------------------------
                                        Name:  Marlayna J. Jeanclerc
                                        Title: Vice President