EQUITY COMMITMENT AGREEMENT

EQUITY COMMITMENT AGREEMENT (“Agreement”), dated as of March 1, 2006, between BERKSHIRE HATHAWAY INC., a corporation duly organized and validly existing under the laws of the State of Delaware (“ Berkshire ”), and MIDAMERICAN ENERGY HOLDINGS COMPANY, a corporation duly organized and validly existing under the laws of the State of Iowa (“ MEHC ”).

RECITALS

WHEREAS, it is necessary from time to time for MEHC to fund the capital requirements of its various subsidiaries; and

WHEREAS, Berkshire, as the owner of certain of the equity interests in MEHC, anticipates that it will benefit from MEHC’s funding of such capital requirements; and

WHEREAS, Berkshire desires to provide for equity contributions to MEHC for the express purpose of funding such capital requirements;

AGREEMENT

NOW THEREFORE, in consideration of the foregoing recitals and the covenants and agreements as hereinafter set forth, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, each of the parties hereto hereby agrees as follows:

Section 1. Definitions . The following terms shall have the following meanings when used in this Agreement:

“Common Stock Valuation ” means the per share value of MEHC’s common stock on a given date, as mutually agreed to by MEHC and the Equity Contributor, or if MEHC and the Equity Contributor cannot agree on such per share value, the amount determined pursuant to the appraisal procedure specified in Section 2(b) .

“ Equity Contribution ” means a capital contribution to MEHC required to be made, or caused to be made, by Berkshire in accordance with Section 2 hereof.

“ Equity Contributor ” means Berkshire and any successor and assign as permitted by this Agreement.

“ Equity Requisition Certificate ” means a certificate substantially in the form of Exhibit A hereto.

“ Equivalent Common Shares ” means, with respect to any given Equity Contribution, the closest whole number of duly authorized, validly issued, fully paid and non-assessable shares of MEHC’s common stock calculated by dividing the amount of such Equity Contribution by the Common Stock Valuation on the date of such Equity Contribution.

“ Maximum Equity Amount ” means $3,500,000,000.

Section 2. Equity Contributions . (a) From and after the date hereof until February 28, 2011 (the “Termination Date”), the Equity Contributor shall contribute, or cause to be contributed, to MEHC from time to time, on or prior to the date specified in the Equity Requisition Certificate referred to below, any Equity Contribution (in an amount equal to $250,000,000 or any integral multiple thereof) requested by MEHC in an Equity Requisition Certificate duly authorized by the MEHC Board of Directors and received by the Equity Contributor at least 180 calendar days prior to such date; provided , however , that such Equity Contribution, together with the aggregate amount of all previous Equity Contributions made by Berkshire and other MEHC equity holders pursuant to this Section 2 shall not exceed the Maximum Equity Amount. Equity Contributor shall not be required to contribute, or cause to be contributed, any Equity Contribution unless Equity Contributor shall have received and not previously satisfied an appropriately completed Equity Requisition Certificate for the amount of such contribution from MEHC at least 180 calendar days prior to the date on which such Equity Contribution is to be made. MEHC shall evidence each Equity Contribution by issuing in the name of the Equity Contributor or its designee the Equivalent Common Shares associated with such Equity Contribution and any such Equity Contribution shall be made simultaneously with and conditioned upon issuance to the Equity Contributor of the Equivalent Common Shares.

(b)   In the event that MEHC and the Equity Contributor cannot agree on the Common Stock Valuation associated with any given Equity Contribution, then the Common Stock Valuation shall be the fair market value of a share of MEHC’s common stock assuming MEHC is valued on a going-concern basis as though it were a publicly traded company and without a controlling shareholder and without attributing any change of control premium to the sale of such share, and taking into account all aspects of MEHC’s capital structure including all outstanding options, determined as follows:

(i) As soon as reasonably practicable, but in any event within fifteen (15) days, following the delivery of an Equity Requisition Certificate, MEHC shall prepare and deliver to Berkshire a statement setting forth the good faith calculation of the Common Stock Valuation as of the date of the Equity Requisition Certificate, together with detail reasonably sufficient for Berkshire to evaluate the accuracy of such calculation (the “Valuation Statement”).

(ii) Unless Berkshire, within fifteen (15) days after receipt of the Valuation Statement, delivers to MEHC a notice (the “Dispute Notice”) objecting in good faith to the Valuation Statement, the Valuation Statement shall be deemed to be final, and the Common Stock Valuation set forth therein shall be deemed to be the “Final Common Stock Valuation”.

(iii) If Berkshire delivers a Dispute Notice and if MEHC and Berkshire are unable to agree upon a Final Common Stock Valuation within thirty (30) days of the date of the Dispute Notice, then either Berkshire or MEHC may elect to submit the calculation of the Common Stock Valuation to an independent appraiser who shall be a member of a reputable valuation firm or investment bank which is designated jointly by Berkshire and MEHC. Such appraiser shall determine the Common Stock Valuation at the date of the Equity Requisition Certificate, and such Common Stock Valuation shall be deemed to be the Final Common Stock Valuation with respect to such Equity Requisition Certificate.

(c)   Submission of an Equity Requisition Certificate shall be at MEHC’s discretion and this Agreement does not create any obligation requiring MEHC to request an Equity Contribution. MEHC shall use its reasonable best efforts to fund the obligations of MEHC and its subsidiaries and minimize or avoid requests for an Equity Contribution.

(d)   Contemporaneous with the delivery of any Equity Requisition Certificate to Berkshire under this Agreement, MEHC shall also deliver a copy of such Equity Requisition Certificate to the then current holders of record of each share of MEHC’s common stock. Within one (1) business day of the determination of the Common Stock Valuation associated with such Equity Requisition Certificate, MEHC shall also send a notice thereof to each such holder (a “Common Stock Valuation Notice”). If any such holder sends a written notice to MEHC and Berkshire within thirty (30) calendar days of the date of such Common Stock Valuation Notice (or such lesser number of days as may be remaining prior to the date specified in the Equity Requisition Certificate) of such holder’s irrevocable commitment to participate in such Equity Contribution, then Berkshire’s portion of the Equity Contribution shall be reduced by an amount equal to the product of (i) the Equity Contribution and (ii) the ratio of (A) the aggregate number of shares of MEHC’s common stock then held by such holder determined on a diluted basis over (B) the total number of shares of MEHC’s common stock determined on a diluted basis (a “Proportionate Reduction”). MEHC and Berkshire hereby agree to permit such holder to participate in the Equity Contribution in an amount equal to the Proportionate Reduction and receive the Equivalent Common Shares associated therewith. If any such holder fails to timely fund such irrevocable commitment, Berkshire shall provide such portion of the Equity Contribution and the applicable Equivalent Common Shares shall be issued to Berkshire, without prejudice to MEHC’s rights to seek damages for breach of any holder’s irrevocable commitment.

Section 3. Use of Equity Contribution . MEHC shall use the proceeds of an Equity Contribution only for the purpose of (a) paying when due MEHC debt obligations and (b) funding the general corporate purposes and capital requirements of MEHC’s regulated subsidiaries.

Section 4. Obligations Unconditional; Waivers . (a) The obligations of the Equity Contributor under Section 2 shall be absolute, unconditional and irrevocable under any and all circumstances, and shall be performed (to the fullest extent permitted by applicable law) by the Equity Contributor regardless of:

(i) the existence of any indebtedness owing by MEHC or any affiliate thereof to the Equity Contributor or of any setoff, abatement, counterclaim, recoupment, defense or other right