Exhibit 10.22(a)

CABOT OIL & GAS CORPORATION

SAVINGS INVESTMENT PLAN

(As Amended and Restated Effective January 1, 2006)

First Amendment

Cabot Oil & Gas Corporation, a Delaware corporation (the “Company”), having
established the Cabot Oil & Gas Corporation Savings Investment Plan, as amended
and restated January 1, 2006 (the “Plan”), and having reserved the right under
Section 10.4 thereof to amend the Plan, does hereby amend the Plan, effective as
of January 1, 2006, as follows:

 

  1. Section 13.7(6)(b) of the Plan is hereby amended in its entirety to read as
follows:

 

  “(b) In determining the present value of the cumulative accrued benefit (for
this purpose using the actuarial assumptions set forth in the applicable pension
plan) or the amount of the account of any employee, such present value or
account balance shall be increased by the amount in dollar value of the
aggregate distributions made with respect to the employee under the Plan and any
plan aggregated with the Plan under Section 416(g)(2) of the Code during the
1-year period ending on the Determination Date. The preceding sentence shall
also apply to distributions under a terminated plan which, had it not been
terminated, would have been aggregated with the Plan under
Section 416(g)(2)(A)(i) of the Code. In the case of a distribution made for a
reason other than severance from employment, death, or disability, this
provision shall be applied by substituting “5-year period” for “1-year period.”
The amounts will include distributions to employees representing the entire
amount credited to their accounts under the applicable plan. The accrued
benefits and accounts of any individual who has not performed services for a
Considered Company during the 1-year period ending on the Determination Date
shall not be taken into account.”

IN WITNESS WHEREOF, the Company has caused this Amendment to be executed by its
duly authorized officer this 12th day of December 2007, but effective as
specified herein.

 

CABOT OIL & GAS CORPORATION By:  

/s/ Abraham D. Garza

Name:   Abraham D. Garza Title:   Vice President, Human Resources