**EXHIBIT
      10.72**





Execution
      Copy




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”.






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(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:






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(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 or claim which the Equity Contributor may have against
      MEHC, any affiliate thereof or any other person; or





(ii)
      the
      availability of other possible funding sources to MEHC or any of its
      subsidiaries.





(b)  The
      obligation of the Equity Contributor to make or cause to be made an Equity
      Contribution as provided in Section
      2 shall
      not be affected by (to the fullest extent permitted by applicable law) any
      abatement, reduction, limitation, impairment, termination, setoff, defense,
      counterclaim or recoupment whatsoever or any right to any thereof, and shall
      not
      be released, discharged or in any way affected by any reorganization,
      arrangement, compromise or plan affecting MEHC or any affiliate
      thereof.





(c)  In
      respect of the obligation of the Equity Contributor to make or cause to be
      made
      Equity Contributions as provided in Section
      2 ,
      the
      Equity Contributor hereby unconditionally (to the fullest extent permitted
      by
      applicable law):





(i)
      waives notice of acceptance hereof and of any defaults by MEHC or any affiliate
      thereof in the payment of any amounts due, protest, presentment, or any other
      act or omission or thing or delay to do any other act or thing which might
      in
      any manner or to any extent vary the risk of such Equity Contributor, but does
      not waive the conditions set forth in Section 2(a);





(ii)
      agrees that this Agreement shall remain in full force and effect without regard
      to, and shall not be affected or impaired by, any invalidity, irregularity
      or
      unenforceability in whole or in part of any other document;





(iii)
      agrees that no failure or delay on the part of MEHC or any other person in
      exercising any right, power or privilege hereunder or under any other document
      and no course of dealing between such Equity Contributor on the one hand, and
      MEHC, any affiliate thereof on the other hand, shall operate as a waiver
      thereof, nor shall any single or partial exercise of any right, power or
      privilege hereunder preclude any other or further exercise thereof or the
      exercise of any other right, power or privilege hereunder;





(iv)
      agrees that the rights and remedies herein provided are cumulative and not
      exclusive of any rights or remedies which MEHC would otherwise have;
      and






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(v)
      agrees that this Agreement shall be discharged only by complete performance
      and
      payment in full of the obligations contained herein or by occurrence of the
      Termination Date (so long as no Equity Requisition Certificate remains
      outstanding and unsatisfied) and that the Equity Contributor shall have no
      right
      to withhold or set-off against any payments due for any reason.





Section
      5. Representations
      and Warranties :
      Berkshire hereby represents and warrants that:





(a)  it
      is a
      corporation duly formed, validly existing and in good standing under the laws
      of
      the State of Delaware, and it is duly qualified and authorized to do business
      and is in good standing as a foreign corporation in each jurisdiction in which
      it owns or leases real property or in which the nature of its business requires
      it to be so qualified, except where the failure to be so qualified and
      authorized to do business and in good standing would not reasonably be expected
      to materially adversely affect its ability to perform its obligations under
      this
      Agreement;





(b)  it
      has
      all necessary power and authority to execute and deliver this Agreement and
      to
      perform all of its obligations hereunder, and its execution, delivery and
      performance of this Agreement have been duly authorized by all necessary action
      on its part and do not require any approval or consent of any holder (or any
      trustee for or agent of any holder) of any indebtedness or other obligation
      of
      it or any other person or entity, other than approvals or consents which have
      previously been obtained and which are in full force and effect;




(c)  it
      has
      duly executed and delivered this Agreement and this Agreement constitutes the
      valid and binding obligation of it enforceable against it in accordance with
      its
      terms, except as enforceability may be limited by general equitable principles
      and applicable bankruptcy, insolvency, reorganization, moratorium or other
      similar laws affecting the rights of creditors generally;





(d)  the
      execution and delivery by it of the Agreement and the performance by it of
      its
      obligations hereunder do not (i) conflict with its certificate of incorporation
      or bylaws, (ii) conflict with or result in any breach of any of the terms,
      covenants, conditions or provisions of, or constitute a default under, any
      indenture, mortgage, deed of trust, agreement or other material instrument
      to
      which it is a party or by which it or any of its material properties or assets
      is bound, or (iii) conflict with any applicable laws, or any order, writ,
      injunction or decree of any court or governmental authority binding on it or
      its
      material properties or assets, except in the case of clauses (ii) and (iii)
      any
      such conflict, breach or default which would not reasonably be expected to
      materially adversely affect its ability to perform its obligations under this
      Agreement;





(e)  no
      governmental approvals or other consents or approvals are required in connection
      with the execution, delivery and performance by it of this Agreement, other
      than
      governmental approvals which the failure to obtain would not reasonably be
      expected to materially adversely affect its ability to perform under this
      Agreement;






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(f)  it
      is in
      compliance with all applicable laws except to the extent that the failure to
      comply therewith would not reasonably be expected to materially adversely affect
      its ability to perform its obligations under this Agreement; and





(g)  no
      litigation, investigation or proceeding of or before any arbitrator or
      governmental authority is pending or, to the best of its knowledge, threatened
      against it or any of its properties, rights, revenues or assets which would
      reasonably be expected to materially adversely affect its ability to perform
      its
      obligations under this Agreement.





Section
      6. Expenses .
      Each of
      MEHC and Equity Contributor hereby agrees to pay all of its respective costs,
      including reasonable attorneys' fees, incurred with respect to the enforcement
      of the provisions of this Agreement.





Section
      7. Miscellaneous .





a)  Notices .
      All
      notices to be given hereunder shall be in writing (including by telecopy),
      and
      shall be deemed to have been duly given or made when delivered by hand, or,
      in
      the case of telecopy notice, when confirmation is received, at the following
      addresses:





Berkshire:
            Berkshire
                Hathaway Inc.
              1440
                Kiewit Plaza
              Omaha,
                Nebraska 68131Telephone:
                ( 402) 978-5423
              Fax:
                (402) 346-3375
              Attn:Chief
                Financial OfficerMEHC:
            MidAmerican
                Energy Holdings Company
              302
                South 32ndStreet
              Omaha,
                Nebraska 68131Telephone:
                (402) 231-1642
              Fax:
                (402) 231-1658
              Attn:General
                Counsel





Each
      of
      Berkshire’s and MEHC’s address for notice hereunder may be changed at any time
      upon notice to the other party given in accordance with this clause
      (a).






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b)  Counterparts .
      This
      Agreement may be executed in separate counterparts, each of which when so
      executed and delivered shall be an original but all such counterparts shall
      constitute one and the same instrument.





c)  Amendments,
      etc.; Termination .
      No
      termination of, or amendment or waiver of any provision of, this Agreement,
      or
      consent to any departure by Berkshire therefrom, shall be effective unless
      the
      same shall be in writing and signed by each of the parties hereto. Any such
      waiver or consent shall be effective only in the specific instance and for
      the
      specific purpose for which given. Notwithstanding the foregoing, (i) this
      Agreement will automatically terminate on the Termination Date; provided,
      however ,
      that
      notwithstanding such termination, Equity Contributor shall have the obligation
      as set forth in Section 2 to make any Equity Contribution validly requested
      by
      MEHC pursuant to this Agreement prior to the Termination Date and (ii) the
      provisions of Sections 4, 6 and 7 shall survive such termination.





d)  Successors
      and Assigns .
      This
      Agreement shall not be assignable by either Equity Contributor or MEHC without
      the prior written consent of the other party.





e)  No
      Third Party Beneficiaries .
      Except
      as provided in clause (d) of this Section
      7 ,
      nothing
      herein contained shall confer any right upon any person other than the parties
      hereto.





f)  Headings
      Descriptive .
      The
      headings of the several sections of this Agreement are inserted for convenience
      only and shall not in any way affect the meaning or construction of any
      provision of this Agreement.





g)  Survival .
      All
      agreements, statements, representations and warranties made by the Equity
      Contributor herein or in any certificate or other instrument delivered by the
      Equity Contributor or on its behalf under this Agreement shall survive the
      execution and delivery of this Agreement until the satisfaction in full by
      the
      Equity Contributor of its obligations hereunder.


h)  Consent
      to Jurisdiction .
      Any
      legal action or proceeding by or against the Equity Contributor with respect
      to
      or arising out of this Agreement may be brought in or removed to the courts
      of
      the State of Nebraska, or of the United States of America located in the State
      of Nebraska. By execution and delivery of this Agreement, each Equity
      Contributor accepts, for itself and in respect of its property, generally and
      unconditionally, the jurisdiction of the aforesaid courts for legal proceedings
      arising out of or in connection with this Agreement. The Equity Contributor
      hereby waives any right to stay or dismiss any action or proceeding under or
      in
      connection with this Agreement brought before the foregoing courts on the basis
      of forum
      non-conveniens or
      improper venue.





i)  Waiver
      of Jury Trial .
      EACH OF
      THE EQUITY CONTRIBUTOR AND MEHC HEREBY KNOWINGLY, VOLUNTARILY AND INTENTIONALLY
      WAIVES ANY RIGHTS IT MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION
      BASED HEREON, OR ARISING OUT OF, UNDER OR IN CONNECTION WITH, THIS AGREEMENT,
      OR
      ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN)
      OR ACTIONS OF THE OTHER PARTIES HERETO.





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j)  Reinstatement .
      This
      Agreement shall continue to be effective or be reinstated, as the case may
      be,
      if at any time any amount received by MEHC hereunder or pursuant hereto is
      rescinded and repaid to the Equity Contributor or is otherwise restored or
      returned to the Equity Contributor by MEHC upon the insolvency, bankruptcy,
      dissolution, liquidation or reorganization of the Equity Contributor, MEHC
      or
      any affiliate thereof or upon the appointment of any intervenor or conservator
      of, or trustee or similar official for, the Equity Contributor, MEHC or any
      affiliate thereof, or any substantial part of the Equity Contributor's, MEHC's
      or any such affiliate's assets, or upon the entry of an order by any court
      avoiding the payment of such amount, all as though such payments had not been
      made.





k)  Entire
      Agreement .
      This
      Agreement constitutes the entire agreement and understanding of Berkshire and
      MEHC relating to the subject matter hereof and supersedes all prior agreements
      and understandings among Berkshire and MEHC, whether written or oral, relating
      to the subject matter hereof.





l)  Severability .
      In case
      any provision of or obligation under this Agreement shall be invalid, illegal
      or
      unenforceable in any jurisdiction, the validity, legality and enforceability
      of
      the remaining provisions or obligations, or of such provision or obligation
      in
      any other jurisdiction, shall not in any way be affected or impaired
      thereby.





m)  Governing
      Law .
      This
      Agreement shall be governed by and construed in accordance with the laws of
      the
      State of Nebraska without regard to the conflict of law rules
      thereof.





n)  Limitation
      of Liability .
      Notwithstanding anything else in this Agreement or any other document,
      Berkshire’s liability in respect of this Agreement is limited to the Maximum
      Equity Amount. No shareholder, officer, employee, controlling person, executive,
      director, agent or affiliate of Berkshire shall be liable for any payments
      under
      this Agreement or any other obligations of Berkshire due to MEHC.







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IN
      WITNESS WHEREOF, the parties hereto have caused their duly authorized officers
      to execute and deliver this Equity Commitment Agreement as of the date first
      above written.




BERKSHIRE
              HATHAWAY
              INC.By:
            /s/ 
Marc
              D. HamburgName:  Marc D. HamburgTitle: 
Vice
              President







MIDAMERICAN
              ENERGY
              HOLDINGS COMPANYBy:
            /s/ 
              Douglas L. AndersonName:  Douglas L.
              AndersonTitle: 
              Senior Vice President






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EXHIBIT
      A





FORM
      OF EQUITY REQUISITION CERTIFICATE





[DATE]





Berkshire
      Hathaway Inc.


1440
      Kiewit Plaza


3555
      Farnam Street


Omaha,
      NE
      68131


Attention:





Ladies
      and Gentlemen:





This
      Equity Requisition Certificate is delivered to you pursuant to Section
      2 of that
      certain Equity Commitment Agreement, dated as of ________________, 2006 (the
      " Equity
      Commitment Agreement "),
      by
      and among you and MEHC. This request has been authorized by the MEHC Board
      of
      Directors. Capitalized terms used herein but not otherwise defined herein shall
      have the meanings assigned to them in the Equity Commitment
      Agreement.





We
      hereby
      request that, in exchange for issuance of Equivalent Common Shares, you
      contribute an Equity Contribution to MEHC in the amount and on or prior to
      the
      date set forth below:





Amount
      of
      Equity Contribution: $_________________





Date
      of
      Equity Contribution: _____________________








Very
      truly yours,





MIDAMERICAN
      ENERGY HOLDINGS COMPANY











By:
            _________________________


Name:


Title:












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