Exhibit 10.2

AMENDMENT TO WORKING CAPITAL LOAN AGREEMENT

This AMENDMENT TO WORKING CAPITAL LOAN AGREEMENT (the “Amendment”), dated as of
December 1, 2008 (the “Effective Date”), among MGG MIDSTREAM HOLDINGS, L.P., a
limited partnership organized and existing under the laws of the State of
Delaware with principal offices at One Williams Center, Tulsa, Oklahoma 74172
(“Lender”), MAGELLAN MIDSTREAM HOLDINGS, L.P., a limited partnership organized
and existing under the laws of the State of Delaware with principal offices at
One Williams Center, Tulsa, Oklahoma 74172 (“Borrower”), Carlyle/Riverstone MLP
Holdings, L.P., Madison Dearborn Capital Partners IV, L.P., Schwerin Company,
LLC, Randolph Street Partners V and Special Co-Invest Partners I. Unless
otherwise indicated, all capitalized terms used herein and not otherwise defined
shall have the respective meanings provided such terms in the Working Capital
Loan Agreement referred to below.

W I T N E S S E T H :

WHEREAS, the Borrower and Lender are parties to that certain Working Capital
Loan Agreement, dated as of January 1, 2008 (as amended, modified and/or
supplemented to, but not including, the date hereof, the “Working Capital Loan
Agreement”);

WHEREAS, subject to the terms and conditions of this Amendment, the parties
hereto wish to amend certain provisions of the Working Capital Loan Agreement as
herein provided;

NOW, THEREFORE, it is agreed:

 

I. Amendments to Working Capital Loan Agreement.

1. The recitals to the Working Capital Loan Agreement are hereby amended by
deleting the period at the end thereof and inserting the following in lieu
thereof:

“, CARLYLE/RIVERSTONE MLP HOLDINGS, L.P. (“Carlyle/Riverstone”), MADISON
DEARBORN CAPITAL PARTNERS IV, L.P. (“Madison Dearborn”), SCHWERIN COMPANY, LLC
(“Schwerin”), RANDOLPH STREET PARTNERS V (“Randolph Street”) and SPECIAL
CO-INVEST PARTNERS I (“Special Co-Invest,” and together with Carlyle/Riverstone,
Madison Dearborn, Randolph Street and Special Co-Invest, the “Additional
Parties” and each individually an “Additional Party”). Each Additional Party is
a party hereto solely for purposes of Section 6 of this Agreement.”

2. Section 2 of the Working Capital Loan Agreement and the definition of
Maturity Date contained therein is hereby amended by replacing the phrase
“December 31, 2008” with “March 31, 2009” in lieu thereof.

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3. Sections 5 through 25 of the Working Capital Loan Agreement are hereby
amended by (i) renumbering Sections 5 through 25 as Sections 7 through 27,
consecutively and respectively, and (ii) adding the following new Section 5:

“Third Party Loan. Borrower will use reasonable efforts to execute an agreement
with a third-party lender pursuant to which such lender will provide Borrower
with loans of no less than an aggregate principal amount outstanding of up to
$2,000,000 (a “Third Party Facility”).”

and (iii) adding the following new Section 6:

“Retention of Assets. Subsequent to (i) the contribution of the general partner
interest of Magellan Midstream Holdings GP, LLC (“MGG GP”) pursuant to that
certain Contribution Agreement (the “Contribution Agreement”), dated as of
December 1, 2008, by and among Lender, Borrower, MGG GP and MGG GP Holdings,
LLC, (ii) the distribution of the common units representing limited partnership
interests of Magellan Midstream Holdings, L.P. and assets in an amount such
that, subsequent to the contribution described in clause (i) hereof and the
distribution described in this clause, the Borrower shall retain assets with a
fair market value equal to $5,000,000 on the date hereof (the “Retained
Assets”), the Borrower shall not, nor shall any Additional Party cause the
Borrower to, distribute any of the Retained Assets prior to the earlier of the
Maturity Date or termination of this Agreement pursuant to Section 10 hereof.
Such Retained Assets shall be free and clear of any and all liens and
encumbrances.”

4. Section 8, renumbered as Section 10 by this Amendment, of the Working Capital
Loan Agreement is hereby amended by adding the following sentence to the end
thereof:

“This Agreement will automatically and immediately terminate upon the execution
of a Third Party Facility. Such termination does not obviate Buyer’s obligation
to pay to Lender all outstanding principal, interest and other payments owed
under this Agreement in full upon such termination.”

5. Section 9, renumbered as Section 11 by this Amendment, of the Working Capital
Loan Agreement is hereby amended by adding the following sentence immediately
preceding the last sentence thereof:

“Notwithstanding any of the foregoing, in no event shall the consummation of the
transactions contemplated by the Contribution Agreement constitute a “Default”
as defined in this Section.”

 

II. Miscellaneous Provisions.

1. The Working Capital Loan Agreement is modified only by the express provisions
of this Amendment and this Amendment shall not constitute a modification,
acceptance or waiver of any other provision of the Working Capital Loan
Agreement except as specifically set forth herein.

 

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2. This Amendment may be executed in any number of counterparts and by the
different parties hereto on separate counterparts, each of which counterparts
when executed and delivered shall be an original, but all of which shall
together constitute one and the same instrument. A complete set of counterparts
shall be lodged with the Borrower and the Lender.

3. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL
BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF NEW
YORK.

4. This Amendment shall become effective as of the date first written above (the
“Amendment Effective Date”).

5. From and after the Amendment Effective Date, all references in the Working
Capital Loan Agreement shall be deemed to be references to the Working Capital
Loan Agreement, as amended and modified hereby.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their proper officers on the date and year first above written.

 

MGG MIDSTREAM HOLDINGS, L.P. By:   MGG Midstream Holdings GP, LLC, its general
partner By:   /s/ Don R. Wellendorf Name: Don R. Wellendorf Title: President and
Chief Executive Officer

 

MAGELLAN MIDSTREAM HOLDINGS, L.P. By:   Magellan Midstream Holdings GP, LLC, its
general partner By:   /s/ John D. Chandler Name: John D. Chandler Title: Chief
Financial Officer

 

CARLYLE/RIVERSTONE MLP HOLDINGS, L.P. By:   Carlyle/Riverstone Energy Partners
II, L.P., its general partner By:   C/R Energy GP II, LLC, its general partner
By:   /s/ Thomas Walker Name: Thomas Walker Title: Authorized Person

 

SIGNATURE PAGE

AMENDMENT TO WORKING CAPITAL LOAN AGREEMENT

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MADISON DEARBORN CAPITAL PARTNERS IV, L.P. By:   Madison Dearborn Partners IV,
L.P., its general partner By:   Madison Dearborn Partners, LLC, its general
partner By:   /s/ Mark. B. Tresnowski Name: Mark. B. Tresnowski Title:
Authorized Person

 

SCHWERIN COMPANY, LLC By:   /s/ Michael F. Schwerin Name: Michael F. Schwerin
Title: Authorized Person

 

RANDOLPH STREET PARTNERS V By:   /s/ Jack S. Levin Name: Jack S. Levin Title:
Authorized Person

 

SPECIAL CO-INVEST PARTNERS I By:   /s/ William S. Kirsch Name: William S. Kirsch
Title: Authorized Person

 

SIGNATURE PAGE

AMENDMENT TO WORKING CAPITAL LOAN AGREEMENT