Exhibit 10.41

SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE CONFIDENTIAL TREATMENT FOR THOSE TERMS HAS BEEN REQUESTED. THE REDACTED MATERIAL HAS BEEN SEPERATELY FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION, AND THE TERMS HAVE BEEN MARKED AT THE APPROPRIATE PLACE WITH TWO ASTERISKS (**).

AMENDMENT TO
RAW PRODUCT PURCHASE AGREEMENT

This
Amendment to the Raw Product Purchase Agreement (the "Amendment") is made and entered into effective as of December 1, 2009 (the
"Effective Date") by and between Targa Liquids Marketing and Trade ("Targa"),
successor-in-interest to Dynegy Liquids Marketing and Trade, and MarkWest Energy East Texas Gas Company, L.L.C. ("MarkWest"),
successor-in-interest to MarkWest Energy East Texas Gas Company, L.P. Targa and MarkWest may be referred to collectively as the "Parties" or singularly as a "Party".

RECITALS:

WHEREAS,
the Parties entered into that certain Raw Product Purchase Agreement (the "Agreement") dated
February 11, 2005, with an effective start date on December 1, 2005; and

WHEREAS,
the Parties wish to amend certain provisions of the Agreement.

NOW
THEREFORE, in consideration of the premises and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties agree as follows:

1.     Paragraph 1
("Term") of the first page of the Agreement shall be amended by deleting that paragraph in its entirety and replacing it with the
following:



2.     "Approx.
Volume" in Paragraph 2 of the first page of the Agreement shall be revised to read "**barrels per day."

3.     "Attachment
AVolumes, Pricing and Special Terms" shall be amended effective as of December 1, 2009, by deleting paragraphs A, B, and C in their
entirety and replacing paragraphs A and B with the following (paragraph C will be deleted and not replaced):



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Gas Price =

The**as published in the first issue INSIDE F.E.R.C.'s GAS MARKET REPORT, for natural gas for the month in which the Fractionation Fee is being computed in dollars per
million British thermal units ($/mmBtu)Elec =

The combined average cost of purchased electricity, in cents per kilowatt hour, at**during the preceding monthCPIU =

The latest available Consumer Price Index, all Urban Consumers ("CPIU), U.S. city average, All Items, 1982-84 = 100 (Unadjusted) as published by the United States Bureau of Labor Statistics (the "BLS") or any
successor agency thereto ("CPI-Index"). The CPIU Index shall be taken from the data published by the BLS either electronically at its then current internet site or as same is published in hardcopy form.


4.     "Attachment
AVolumes, Pricing and Special Terms" shall be further amended effective December 1, 2009, by adding the following sentence to the end of
paragraph F ("Adequate Assurance"):



5.     "Attachment
BGeneral Terms and Conditions" shall be amended by deleting paragraph D in Section 1 and replacing it with the
following:



7.     "Attachment
BGeneral Terms and Conditions" shall be amended by adding a second paragraph to Section 17 as follows:



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IN
WITNESS WHEREOF, the Parties have each caused their duly authorized representative to execute this Amendment effective as of the Effective Date.

Targa Liquids Marketing and Trade

MarkWest Energy East Texas Gas Company, L.L.C.By:

/s/ Michael A. Heim

By:

/s/ John MollenkopfName:

Michael A. Heim

Name:

John MollenkopfTitle:

Executive Vice President and COO

Title:

Senior Vice President and COO


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