Exhibit 4.25

AMENDMENT NO. 6

TO

ADOPTION AGREEMENT #001

RELATING TO

RETIREMENT SAVINGS TRUST AND PLAN

A PROTOTYPE PLAN SPONSORED BY

CALFEE, HALTER & GRISWOLD LLP

NORTH COAST ENERGY, INC.

EMPLOYEES’ PROFIT SHARING TRUST AND PLAN

Restatement Date:  January 1, 2003

WITNESSETH:

WHEREAS, the Company amended and restated the North Coast Energy, Inc. Employees’ Profit Sharing Trust and Plan (hereinafter called the “Plan”), effective January 1, 2003, by completing and executing an Adoption Agreement (hereinafter called the “Adoption Agreement”) to the Calfee, Halter & Griswold Regional Prototype Plan; and

WHEREAS, the Company reserved the right to amend the Adoption Agreement and the Trust and Plan pursuant to Section 28.1 thereof; and

WHEREAS, the Company desires to amend the Plan in order to modify the safe harbor definition of “Compensation”in the Plan;

NOW, THEREFORE, pursuant to Section 28.1 of the Plan, the Company hereby amends the Plan, effective as of January 1, 2006, as follows: