EXHIBIT 10.36

                                 FIFTH AMENDMENT
                                       OF
                         USG CORPORATION RETIREMENT PLAN

            (As Amended and Restated Effective as of January 1, 1999)

      WHEREAS, USG Corporation Retirement Plan (the "plan") is maintained by USG
Corporation (the "company"), which plan was amended and restated on December 29,
1999, effective as of January 1, 1999; and

      WHEREAS, it now is deemed desirable and in the best interests of the
employers under the plan and their employees to further amend the plan;

      NOW, THEREFORE, pursuant to the amending power reserved to the company
under subsection 14.1 of the plan, the plan is further amended, as follows:

      1. By substituting the following for subsection 2.1 of the plan, effective
June 27, 2005:

      "2.1 Covered Employee, Participant, Eligibility Date

            The term `covered employee' means an employee who is a member of a
      group of employees of an employer to which the plan has been and continues
      to be extended by the company or by agreement, and who, effective January
      1, 2000, is not classified by the employer as a temporary employee. The
      term `participant' means an employee of a USG Company who, after becoming
      eligible for participation in the plan, is enrolled in the plan pursuant
      to this Section 2 and also means a former employee of the USG Companies
      who either is receiving benefits under the plan or is entitled to receive
      benefits under the plan commencing on a future date. The term `eligibility
      date' means for any employee the date that is determined, in accordance
      with uniform and consistent rules established by the committee, by
      reference to (and not later than the 90 days after) the date on which the
      employee first performs an hour of service as a covered employee. In the
      case



      of an employee who declines to make contributions under subsection 2.5
      when the employee is first eligible to do so, the term `eligibility date'
      means the first subsequent pay date after the employee's enrollment form
      is received and processed by the employee's employer, as determined in
      accordance with rules established by the committee. In the case of a
      former employee who is reemployed by an employer, the term `eligibility
      date' also includes any other date described in subparagraphs 9.1(a) and
      9.2(b) on which such employee is entitled to become enrolled in the plan.
      If an employee of a USG Company becomes a covered employee more than six
      months after the date the employee completes twelve months of employment
      with the USG Companies, the date the employee so becomes a covered
      employee also shall be an `eligibility date.' For purposes of determining
      eligibility to become a participant in the plan, the term `employee' for
      any plan year means any individual who is treated and/or classified by the
      employer for such plan year as an employee for purposes of employment
      taxes and wage withholding for Federal income tax. Except as specifically
      provided in subparagraph 2.8(c), individuals who perform services for an
      employer as independent contractors, leased employees, or through agencies
      are not employees of the employer and therefore are not eligible for
      benefits under this plan. If an individual is not considered to be an
      employee of an employer for purposes of employment taxes and wage
      withholding, a subsequent determination by the employer, any governmental
      agency or court that the individual is a common law employee of the
      employer, even if such determination is applicable to prior years, will
      not have a retroactive effect for purposes of eligibility to participate
      in the plan for any plan year. A temporary employee is an employee who is
      classified as such by the employer and is employed usually for less than
      90 days with a specified date beyond which employment will not continue;
      interns (i.e. students who are employed during summer and other vacations)
      and co-op students (i.e. students who receive school credit for employment
      with the employer) are considered temporary employees."

      2. By substituting the following for subparagraph 5.5(a), effective March
28, 2005:

            "(a)  If the lump sum actuarially equivalent value of the
                  participant's accrued benefits derived from employer
                  contributions does not exceed $5,000 (but subject to the
                  consent requirements set forth in subparagraph 7.8(a) if the
                  lump sum actuarially equivalent value of the participant's
                  total accrued benefits exceeds $1,000), the lump sum payment
                  will be an amount equal to the lump sum actuarially equivalent
                  value of the participant's total accrued benefits. Unless the
                  participant subsequently is reemployed by an employer and
                  again becomes an active participant and makes the required
                  contributions, no other benefits shall be payable under the
                  plan to, or with respect to, the participant."

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      3. By substituting "$1,000" for "$5,000" where the latter appears in
subsection 5.11 of the plan, effective March 28, 2005.

      4. By substituting the following for subsection 5.11 of the plan,
effective June 27, 2005:

      "5.11 Benefit Commencement Consent Requirements

            If the lump sum actuarially equivalent value of a participant's
      nonforfeitable accrued benefits is greater than $1,000, written consent of
      the participant and, if the participant has an eligible spouse at the time
      of the commencement of the distribution of such benefits, the
      participant's eligible spouse, shall be required before the commencement
      of the distribution of any part of the participant's accrued benefits as
      described in subparagraph 7.8(a). No consent shall be required for any
      payment to a survivor other than an eligible spouse."

      5. By substituting the following for subparagraph 6.3(a) of the plan,
effective March 27, 2005:

            "(a)  If the lump sum actuarially equivalent value of the
                  participant's accrued benefits derived from employer
                  contributions does not exceed $5,000 (but subject to the
                  consent requirements set forth in subparagraph 7.8(a) if the
                  lump sum actuarially equivalent value of the participant's
                  total accrued benefits exceeds $1,000), the lump sum payment
                  will be an amount equal to the lump sum actuarially equivalent
                  value of the participant's total accrued benefits. Unless the
                  participant subsequently is reemployed by an employer and
                  again becomes an active participant and makes the required
                  contributions, no other benefits shall be payable under the
                  plan to, or with respect to, the participant."

      6. By substituting $1,000" for "$5,000" where the latter appears in
subsection 6.7 of the plan, effective March 28, 2005.

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      7. By substituting the following for subsection 6.7 of the plan, effective
June 27, 2005:

      "6.7 Benefit Commencement Consent Requirements

            If the lump sum actuarially equivalent value of a participant's
      nonforfeitable accrued benefits is greater than $1,000, written consent of
      the participant and, if the participant has an eligible spouse at the time
      of the commencement of the distribution of such benefits, the
      participant's eligible spouse, shall be required before the commencement
      of the distribution of any part of the participant's accrued benefits as
      described in subparagraph 7.8(a). No consent shall be made for any payment
      to a survivor who is not an eligible spouse."

      8. By substituting "$1,000" for "$5,000" where the latter appears in
subparagraph 7.8(a) and in subsection 7.9 of the plan, effective March 28, 2005.

      9. By substituting the following for subsection 7.9 of the plan, effective
June 27, 2005:

      "7.9 Payment of Small Amounts

            If the lump sum actuarially equivalent value of a participant's
      accrued benefits (as defined in subparagraph 7.10(a)) does not exceed
      $1,000, or if the participant's accrued benefits are payable to a
      participant's eligible spouse because of the death of the participant
      before the participant's benefit commencement date and the lump sum
      actuarially equivalent value of such benefits does not exceed $1,000, a
      lump sum payment equal to the lump sum actuarially equivalent value of
      such benefits shall be paid to the participant, or the participant's
      eligible spouse, as the case may be. For purposes of this subsection, the
      lump sum actuarially equivalent value shall be determined in accordance
      with paragraph A-4 of Exhibit A. If a participant's accrued benefits
      derived from employer contributions are zero, the participant shall be
      deemed to have received a distribution of such benefits."

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      IN WITNESS WHEREOF, the company has caused these presents to be signed by
its officer thereunto duly authorized this 4th day of August, 2005.

                                          USG CORPORATION

                                          By: /s/ Peter K. Maitland
                                              ----------------------------------
                                              Vice President, Compensation
                                              Benefits And Administration

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