EXHIBIT 10.18(F)

                              FOURTH AMENDMENT TO
             THE PIMCO ADVISORS 401(k) SAVINGS AND INVESTMENT PLAN
             -----------------------------------------------------

        WHEREAS, PIMCO Advisors L.P. sponsors the PIMCO Advisors 401(k) Savings
and Investment Plan (the Plan); and

        WHEREAS, Article 9 of the Plan provides the Board of Directors of PIMCO
Advisors L.P. with the authority to amend the Plan at any time; and

        WHEREAS, the Board is desirous of amending the Plan to provide for the
participation of self employed individuals in the Plan;

        NOW THEREFORE, the Plan is amended in the following respects, to wit:

1.  Section 1.09 of the Plan shall be amended by the addition of the following 
    sentence at the end thereof:

        "Compensation for any Self Employed Individual shall be equal to his
    Earned Income."

2.  Article I of the Plan shall be amended by the addition of a new Section 1.42
    to read as follows:

    "1.42 Earned Income means with respect to a Self Employed Individual the net
    earnings from self employment in the trade or business with respect to which
    the Plan is established, for which personal services are a material income
    producing factor."

3.  Article I of the Plan shall be further amended by the addition of a new 
    Section 1.43 to read as follows:

    "1.43 Self Employed Individual means an individual (i) who has Earned Income
    for the taxable year from the trade or business for which the Plan is
    established or who would have had Earned Income but for the fact that the
    trade or business had no net profits for 

 
    the taxable year and (ii) who owns in the aggregate at least 50,000 units of
    Class A and/or Class B limited partner interest in Pimco Advisors L.P. A
    Self Employed Individual shall be treated as an Employee."

4.  Section 4.02(e) shall be amended by the addition of a new paragraph (ix) 
    which shall read as follows:

        "(ix) Matching Contributions made on behalf of Self Employed Individuals
    shall be treated as Elective Deferral Contributions for all purposes under
    the Plan."