Exhibit 10.20

SECOND AMENDMENT TO THE

DYNEGY NORTHEAST GENERATION, INC. SAVINGS INCENTIVE PLAN

WHEREAS, Dynegy Inc. (the “Company”), has established and maintains the Dynegy
Northeast Generation, Inc. Savings Incentive Plan (the “Plan”) for the benefit
of eligible employees of certain participating companies; and

WHEREAS, the Company desires to amend the Plan;

NOW, THEREFORE, BE IT RESOLVED that the Plan shall be, and hereby is amended as
follows, effective as provided below:

I.

Effective as of January 1, 2006, Section 3.3(b) of the Plan is amended in its
entirety to provide as follows;

“(b) With respect to each payroll period, the Employer shall contribute to the
Trust, as Employer Matching Contributions, an amount that equals 34% of the
Before-Tax Contributions that were made pursuant to Section 3.1 on behalf of
each of the Participants whose terms and conditions of employment are governed
by a collective bargaining agreement during such payroll period and that were
not in excess of 6% of each such Participant’s Compensation for such payroll
period.”

II.

Except as modified herein, the Plan shall remain in full force and effect.

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IN WITNESS WHEREOF, the undersigned has caused this Amendment to the Plan to be
executed this 5 day of December 2005, effective as hereinbefore provided.

 

DYNEGY INC. By:   /s/ J. Kevin Blodgett   J. Kevin Blodgett Title:   General
Counsel and EVP, Administration

 

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