FIRST AMENDMENT TO CONTRIBUTION AGREEMENT

Exhibit 2.1

FIRST AMENDMENT TO

CONTRIBUTION AGREEMENT

This First Amendment to Contribution Agreement (the “Amendment”) is made and entered into the 30^th day of March, 2012 among DCP LP Holdings, LLC, a Delaware limited liability company (“HOLDINGS”), DCP Midstream, LLC, a Delaware limited liability company (“MIDSTREAM”), and DCP Midstream Partners, LP, a Delaware limited partnership (“MLP”).

FOR GOOD AND VALUABLE CONSIDERATION, the parties hereto agree as follows:

“Net Working Capital” means, as to the JV, and determined as of the Effective Time, an amount (which may be positive of negative) equal to (i) the total current assets of the JV and its Subsidiaries adjusted for accounts receivable to be zero for the purposes of the Preliminary Settlement Statement minus (ii) the total current liabilities of the JV and its Subsidiaries, in each case determined in accordance with GAAP, as adjusted for the Reserved Liabilities.”

“3.3 Final Settlement Statement. No later than 180 days after the Closing Date and after consultation with MLP, HOLDINGS shall deliver to MLP a revised settlement statement showing in reasonable detail its calculation of the items described in the definition of Total Net Working Capital along with other adjustments or payments contemplated in this Agreement including the amount of any accounts receivable as of the Closing Date reduced by those accounts receivable collected and distributed by the JV to HOLDINGS in accordance with the Preliminary Settlement Statement.”

THE PARTIES HERETO have executed this Amendment to be effective as of the date first above written, notwithstanding the actual date of execution.

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