CABOT OIL & GAS CORPORATION PENSION PLAN

Exhibit 10.23(d)

CABOT OIL & GAS CORPORATION PENSION PLAN

(As Amended and Restated Effective January 1, 2006)

FOURTH AMENDMENT

WHEREAS, effective January 1, 1991, Cabot Oil & Gas Corporation (the “Company”) established the Cabot Oil & Gas Corporation Pension Plan and subsequently amended and restated the Plan, effective January 1, 2006 (the “Plan”); and

WHEREAS, the Company now desires to amend the Plan to provide for changes made necessary or appropriate pursuant to the promulgation of final regulations under Section 415 of the Internal Revenue Code of 1986, as amended;

NOW, THEREFORE, having reserved the right to amend the Plan pursuant to Section 10.1 thereof, the Company hereby amends Article XV of the Plan by deleting the contents thereof and replacing the following in their stead:

15.1 Limitations on Benefits .

In accordance with Treasury Regulation § 1.415(a)-1(d)(3), the Plan incorporates by reference the limitations on benefits under Code Section 415 and as provided under Treasury Regulation § 1.415(b)-1 et seq . (as may be revised or amended from time to time by the Internal Revenue Service), including, but not limited to, Treasury Regulation § 1.415(f)-1. Unless otherwise provided in this Section, the default rules under Code Section 415 Treasury Regulations shall apply with respect to the limitations under this Section.

Notwithstanding any provision of this Plan to the contrary, the Annual Benefit otherwise accrued by or payable to a Participant under the Plan at any time shall not exceed, and shall be limited to (or the rate of accrual reduced to), the “Maximum Permissible Benefit,” which is the lesser of:

In no event shall an Annual Benefit exceeding the above limits be accrued, distributed, or otherwise payable in any optional form of benefit, including the normal form of benefit, at any time from the Plan (or from an annuity contract that will make distributions to a Participant on behalf of the Plan or from an annuity contract distributed under the Plan).

In the event a Participant’s Annuity Starting Date occurs before he attains age 62 or after he attains age 65, his Maximum Permissible Benefit shall be adjusted in accordance with the provisions of Treasury Regulation § 1.415(b)-1(d) or (e), respectively, and, if applicable, under Treasury Regulation § 1.415(b)-1(h).

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The Annual Benefit (without regard to the age at which benefits commence) payable with respect to a Participant does not exceed the Dollar Limit if (i) the benefits (other than benefits not taken into account in the computation of the Annual Benefit under the rules of Treasury Regulation § 1.415(b)-1(b) or (c)) payable with respect to a Participant under the Plan and all other defined benefit plans of the Employer do not in the aggregate exceed $10,000 for the Limitation Year or for any prior Limitation Year (as computed in accordance with Treasury Regulation § 1.415(b)-1(f)(2) and subject to adjustment for participation of less than 10 years); and (ii) the Employer (or a predecessor employer) has not at any time maintained a defined contribution plan in which the Participant participated.

If a Participant has less than 10 years of participation in the Plan, the Dollar Limit, Percentage Limit and the $10,000 amount described above shall be multiplied by a fraction, the numerator of which is the number of years (or part thereof, but not less than one year) of participation in the Plan, and the denominator of which is 10, in accordance with Treasury Regulation § 1.415(b)-1(g).

To the extent a Participant’s Annual Benefit for a Limitation Year exceeds the Participant’s Maximum Permissible Benefit, such result shall be corrected in accordance with procedures available under the Internal Revenue Service’s Employee Plans Compliance Resolution System in effect at the time of the correction.

For purposes of this Section, the following terms shall have the following meanings:

(a) Annual Benefit : The benefit that is payable in the form of a straight life annuity (with no ancillary benefits), as defined in Treasury Regulation § 1.415(b)-1(b). In the event that a Participant’s benefit is payable in a form other than a straight life annuity, his Annual Benefit shall be the benefit payable in the form of the straight life annuity payable on the first day of each month that is actuarially equivalent to the benefit payable in such other form, determined under the rules of Treasury Regulation § 1.415(b)-1(c) and, if applicable, under Treasury Regulation § 1.415(b)-1(h). The actuarial equivalent of a straight life annuity (A) for a form of benefit that is not subject to Section 417(e)(3) of the Code shall be computed using the following assumptions, whichever provides the greater equivalent annual benefit (1) a 5% interest rate assumption and the mortality table used for such form of benefit specified in Section 1.1 of the Plan for that Annuity Starting Date and (2) the interest rate and mortality table (or other tabular factor) specified in Section 1.1 of the Plan; and (B) for a form of benefit that is subject to Section 417(e)(3) of the Code shall be computed using either (I) the “applicable interest rate” under Section 417(e)(3) of the Code (“Applicable Interest Rate”) and the “applicable mortality table” under Section 417(e)(3) of the Code (“Applicable Mortality Table”) for adjusting benefits in the same form; (II) a 5.5% interest rate assumption and the Applicable Mortality Table; or (III) the Applicable Interest Rate and the Applicable Mortality Table, divided by 1.05, whichever provides the greatest annual amount.

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In no event shall a Participant