<PAGE>
Exhibit (b)(1)
AMENDED AND RESTATED
BYLAWS
of
PIMCO FUNDS: MULTI-MANAGER SERIES
(Amended and Restated as of June 8, 2000)
ARTICLE 1
Agreement and Declaration of Trust and Principal Office
1.1 Principal Office of the Trust. A principal office of the Trust
-----------------------------
shall be located in Newport Beach, California. The Trust may have other
principal offices within or without Massachusetts as the Trustees may determine
or as they may authorize.
1.2 Agreement and Declaration of Trust. These Bylaws shall be subject
----------------------------------
to the Second Amended and Restated Agreement and Declaration of Trust, as
amended and restated from time to time (the "Declaration of Trust"), of PIMCO
Funds: Multi-Manager Series, the Massachusetts business trust established by the
Declaration of Trust (the "Trust").
ARTICLE 2
Meetings of Trustees
2.1 Regular Meetings. Regular meetings of the Trustees may be held
----------------
without call or notice at such places and at such times as the Trustees may from
time to time determine, provided that notice of the first regular meeting
following any such determination shall be given to absent Trustees. A regular
meeting of the Trustees may be held without call or notice immediately after and
at the same place as the annual meeting of the shareholders.
2.2 Special Meetings. Special meetings of the Trustees may be held at
----------------
any time and at any place designated in the call of the meeting when called by
the Chairman of the Trustees, the President or the Treasurer or by two or more
Trustees, sufficient notice thereof being given to each Trustee by the Secretary
or an assistant Secretary or by the officer or the Trustees calling the meeting.
2.3 Notice. It shall be sufficient notice to the Trustee of a special
------
meeting to send notice by mail at least forty-eight hours or by telegram, telex
or telecopy or other electronic facsimile transmission method at least
twenty-four hours before the meeting addressed to the Trustee at his or her
usual or last known business or residence address or to give notice to him or
her in person or by telephone at least twenty-four hours before the meeting.
Notice of a
<PAGE>
meeting need not be given to any Trustee if a written waiver of notice, executed
by him or her, before or after the meeting, is filed with the records of the
meeting, or to any Trustee who attends the meeting without protesting prior
thereto or at its commencement the lack of notice to him or her. Neither notice
of a meeting nor a waiver of a notice need specify the purposes of the meeting.
2.4 Quorum. At any meeting of the Trustees a majority of the Trustees
------
then in office shall constitute a quorum. Any meeting may be adjourned from time
to time by a majority of the votes cast upon the question, whether or not a
quorum is present, and the meeting may be held as adjourned without further
notice.
ARTICLE 3
Officers
3.1 Enumeration: Qualification. The officers of the Trust shall be a
--------------------------
President, a Treasurer, a Secretary, and such other officers including a
Chairman of the Trustees, if any, as the Trustees from time to time may in their
discretion elect. The Trust may also have such agents as the Trustees from time
to time may in their discretion appoint. The Chairman of the Trustees, if one is
elected, shall be a Trustee and may but need not be a shareholder; and any other
officer may but does not need to be a Trustee or a shareholder. Any two or more
offices may be held by the same person.
3.2 Election. The President, the Treasurer, and the Secretary shall be
--------
elected annually by the Trustees. Other officers, if any, may be elected or
appointed by the Trustees at said meeting or at any other time. Vacancies in any
office may be filled at any time.
3.3 Tenure. The Chairman of the Trustees, if one is elected, the
------
President, the Treasurer and the Secretary shall hold office until their
respective successors are chosen and qualified, or in each case until he or she
sooner dies, resigns, is removed or becomes disqualified. Each other officer
shall hold office and each agent shall retain authority at the pleasure of the
Trustees.
3.4 Powers. Subject to the other provisions of these Bylaws, each
------
officer shall have, in addition to the duties and powers herein and in the
Declaration of Trust set forth, such duties and powers as are commonly incident
to the office occupied by him or her as if the Trust were organized as a
Massachusetts business corporation and such other duties and powers as the
Trustees may from time to time designate.
3.5 Chairman; President. Unless the Trustees otherwise provide, the
-------------------
Chairman of the Trustees or, if there is none or in the absence of the Chairman,
the President shall preside at all meetings of the shareholders and of the
Trustees. The President shall be the chief executive officer.
-2-
<PAGE>
3.6 Treasurer. The Treasurer shall be the chief financial and
---------
accounting officer of the Trust, and shall, subject to the provisions of the
Declaration of Trust and to any arrangement made by the Trustees with a
custodian, investment adviser or manager, or transfer, shareholder servicing or
similar agent, be in charge of the valuable papers, books of account and
accounting records of the Trust, and shall have such other duties and power as
may be designated from time to time by the Trustees or by the President.
3.7 Secretary. The Secretary shall record all proceedings of the
---------
shareholders and the Trustees in books to be kept therefor, which books or a
copy thereof shall be kept at the principal office of the Trust. In the absence
of the Secretary from any meeting of the shareholders or Trustees, an Assistant
Secretary, or if there be none or if he or she is absent, a temporary secretary
chosen at such meeting shall record the proceedings thereof in the aforesaid
books.
3.8 Resignations. Any officer may resign at any time by written
------------
instrument signed by him or her and delivered to the Chairman, the President or
the Secretary or to a meeting of the Trustees. Such resignation shall be
effective upon receipt unless specified to be effective at some other time.
Except to the extent expressly provided in a written agreement with the Trust,
no officer resigning and no officer removed shall have any right to any
compensation for any period following his or her resignation or removal, or any
right to damages on account of such removal.
ARTICLE 4
Committees
4.1 Quorum; Voting. Except as provided below or as otherwise
--------------
specifically provided in the resolutions constituting a Committee of the
Trustees and providing for the conduct of its meetings, a majority of the
members of any Committee of the Trustees shall constitute a quorum for the
transaction of business, and any action of such a Committee may be taken at a
meeting by a vote of a majority of the members present (a quorum being present)
or evidenced by one or more writings signed by such a majority. Members of a
Committee may participate in a meeting of such Committee by means of a
conference telephone or other communications equipment by means of which all
persons participating in the meeting can hear each other at the same time and
participation by such means shall constitute presence in person at a meeting.
With respect to a Valuation Committee of the Trustees, 50% of more of
the Committee members shall constitute a quorum for the transaction of business.
Except as specifically provided in the resolutions constituting a
Committee of the Trustees and providing for the conduct of its meetings, Article
2, Section 2.3 of these Bylaws relating to special meetings shall govern the
notice requirements for Committee meetings, except that it shall be sufficient
notice to a Valuation Committee of the Trustees to send notice
-3-
<PAGE>
by telegram, telex or telecopy or other electronic means (including by telephone
voice-message or e-mail) at least fifteen minutes before the meeting.
ARTICLE 5
Reports
5.1 General. The Trustees and officers shall render reports at the time
-------
and in the manner required by the Declaration of Trust or any applicable law.
Officers and Committees shall render such additional reports as they may deem
desirable or as may from time to time be required by the Trustees.
ARTICLE 6
Fiscal Year
6.1 General. Except as from time to time otherwise provided by the
-------
Trustees, the initial fiscal year of the Trust shall end on such date as is
determined in advance or in arrears by the Treasurer, the subsequent fiscal
years shall end on such date in subsequent years.
ARTICLE 7
Seal
7.1 General. The seal of the Trust shall consist of a flat faced die
-------
with the word "Massachusetts", together with the name of the Trust and the year
of its organization cut or engraved thereon but, unless otherwise required by
the Trustees, the seal shall not be necessary to be placed on, and its absence
shall not impair the validity of, any document, instrument or other paper
executed and delivered by or on behalf of the Trust.
ARTICLE 8
Execution of Papers
8.1 General. Except as the Trustees may generally or in particular
-------
cases authorize the execution thereof in some other manner, all deeds, leases,
contracts, notes and other obligations made by the Trustees shall be signed by
the President or by the Treasurer and need not bear the seal of the Trust.
ARTICLE 9
Issuance of Share Certificates
9.1 Share Certificates. In lieu of issuing certificates for shares, the
------------------
Trustees or the transfer agent may either issue receipts therefor or may keep
accounts upon the books of the Trust for the record holders of such shares, who
shall in either case be deemed, for all purposes hereunder, to be the holders of
certificates for such shares as if they had accepted such certificates and shall
be held to have expressly assented and agreed to the terms hereof.
-4-
<PAGE>
The Trustees may at any time authorize the issuance of share
certificates. In that event, each shareholder shall be entitled to a certificate
stating the number of shares owned by him, in such form as shall be prescribed
from time to time by the Trustees. Such certificates shall be signed by the
President or any Vice President and by the Treasurer or any Assistant Treasurer.
Such signatures may be facsimile if the certificate is signed by a transfer
agent, or by a registrar, other than a Trustee, officer or employee of the
Trust. In case any officer who has signed or whose facsimile signature has been
placed on such certificate shall cease to be such officer before such
certificate is issued, it may be issued by the Trust with the same effect as if
he were such officer at the time of its issue.
9.2 Loss of Certificates. In case of the alleged loss or destruction or
--------------------
the mutilation of a share certificate, a duplicate certificate may be issued in
place thereof, upon such terms as the Trustees shall prescribe.
9.3 Issuance of New Certificates to Pledgee. A pledgee of shares
---------------------------------------
transferred as collateral security shall be entitled to a new certificate if the
instrument of transfer substantially describes the debt or duty that is intended
to be secured thereby. Such new certificate shall express on its face that it is
held as collateral security, and the name of pledgor shall be stated thereon,
who alone shall be liable as a shareholder and entitled to vote thereon.
9.4 Discontinuance of Issuance of Certificates. The Trustees may at any
------------------------------------------
time discontinue the issuance of share certificates and may, by written notice
to each shareholder, require the surrender of share certificates to the Trust
for cancellation. Such surrender and cancellation shall not effect the ownership
of shares in the Trust.
ARTICLE 10
Provisions Relating to the Conduct of the Trust's Business
10.1 Determination of Net Asset Value Per Share. The net asset value
------------------------------------------
per share of each class and each series of shares of the Trust shall be
determined in accordance with the Investment Company Act of 1940, as amended,
and the rules and regulations thereunder (the "1940 Act") and any related
procedures adopted by the Trustees from time to time.
ARTICLE 11
Shareholders' Voting Powers and Meetings
11.1 Voting Powers. The Shareholders shall have power to vote only (i)
-------------
for the election of Trustees as provided in Article IV, Section 1 of the
Declaration of Trust, provided, however, that no meeting of Shareholders is
-------- -------
required to be called for the purpose of electing Trustees unless and until such
time as less than a majority of the Trustees have been elected by the
Shareholders, (ii) with respect to any Manager or subadviser as provided in
Article IV, Section 6 of the Declaration of Trust to the extent required by the
1940 Act, (iii) with respect to any termination of this Trust to the extent and
as provided in Article IX, Section 4 of the
-5-
<PAGE>
Declaration of Trust, (iv) with respect to any amendment of the Declaration of
Trust to the extent and as provided in Article IX, Section 7 of the Declaration
of Trust, (v) to the same extent as the stockholders of a Massachusetts business
corporation as to whether or not a court action, proceeding or claim should or
should not be brought or maintained derivatively or as a class action on behalf
of the Trust or the Shareholders, and (vi) with respect to such additional
matters relating to the Trust as may be required by law, the Declaration of
Trust, these Bylaws or any registration of the Trust with the Securities and
Exchange Commission (or any successor agency) or any state, or as the Trustees
may consider necessary or desirable. Each whole Share shall be entitled to one
vote as to any matter on which it is entitled to vote and each fractional Share
shall be entitled to a proportionate fractional vote. On any matter submitted to
a vote of Shareholders all Shares of the Trust then entitled to vote shall be
voted by individual series, except (i) when required by the 1940 Act, Shares
shall be voted in the aggregate and not by individual series and (ii) when the
Trustees have determined that the matter affects only the interests of one or
more series, then only Shareholders of such series shall be entitled to vote
thereon. There shall be no cumulative voting in the election of Trustees. Shares
may be voted in person or by proxy. A proxy with respect to Shares held in the
name of two or more persons shall be valid if executed by any one of them unless
at or prior to exercise of the proxy the Trust receives a specific written
notice to the contrary from any one of them. The placing of a Shareholder's name
on a proxy pursuant to telephonic or electronically transmitted instructions
obtained pursuant to procedures reasonably designed to verify that such
instructions have been authorized by such Shareholder shall constitute execution
of such proxy by or on behalf of such Shareholder A proxy purporting to be
executed by or on behalf of a Shareholder shall be deemed valid unless
challenged at or prior to its exercise and the burden of proving invalidity
shall rest on the challenger. Until Shares are issued, the Trustees may exercise
all rights of Shareholders and may take any action required by law, the
Declaration of Trust or these Bylaws to be taken by shareholders.
11.2 Voting Power and Meetings. Meetings of the Shareholders may be
-------------------------
called by the Trustees for the purpose of electing Trustees as provided in
Article IV, Section I of the Declaration of Trust and for such other purposes as
may be prescribed by law, by the Declaration of Trust or by these Bylaws.
Meetings of the Shareholders may also be called by the Trustees from time to
time for the purpose of taking action upon any other matter deemed by the
Trustees to be necessary or desirable. A meeting of Shareholders may be held at
any place designated by the Trustees. Written notice of any meeting of
Shareholders shall be given or caused to be given by the Trustees by mailing
such notice at least seven days before such meeting, postage prepaid, stating
the time and place of the meeting, to each Shareholder at the Shareholder's
address as it appears on the records of the Trust. Whenever notice of a meeting
is required to be given to a Shareholder under the Declaration of Trust or these
Bylaws, a written waiver thereof, executed before or after the meeting by such
Shareholder or his attorney thereunto authorized and filed with the records of
the meeting, shall be deemed equivalent to such notice. A meeting for the
purpose of considering the removal of a person serving as Trustee shall be
called by the Trustees if requested in writing to do so by the holders (which
for purposes of this provision and only this provision shall be the persons
having a
-6-
<PAGE>
voting interest in the shares of the Trust) of not less than 10% of the
outstanding shares of the Trust.
11.3 Quorum and Required Vote. Except when a larger quorum is required
------------------------
by any provision of law or the Declaration of Trust or these Bylaws, thirty
percent of the Shares entitled to vote shall constitute a quorum for the
transaction of business at a Shareholders' meeting, except that where any
provision of law or the Declaration of Trust or these Bylaws permits or requires
that holders of any series shall vote as a series, then thirty percent (unless a
larger quorum is required as specified above) of Shares of that series entitled
to vote shall be necessary to constitute a quorum for the transaction of
business by that series. Any lesser number shall be sufficient for adjournments.
Any adjourned session or sessions may be held, within a reasonable time after
the date set for the original meeting, without the necessity of further notice.
Except when a larger vote is required by any provision of law or the Declaration
of Trust or these Bylaws, a plurality of the quorum of Shares necessary for the
transaction of business at a Shareholders' meeting shall decide any questions
and a plurality of Shares voted shall elect a Trustee, provided that where any
provision of law or of the Declaration of Trust or these Bylaws permits or
requires that the holders of any series shall vote as a series, then a plurality
of the quorum of Shares of that series necessary for the transaction of business
by that series at a Shareholders' meeting shall decide that matter insofar as
that series is concerned.
11.4 Action by Written Consent. Any action taken by Shareholders may
-------------------------
be taken without a meeting if a majority of Shareholders entitled to vote on the
matter (or such larger proportion thereof as shall be required by any express
provision of law or the Declaration of Trust or these Bylaws) consent to the
action in writing and such written consents are filed with the records of the
meetings of Shareholders. Such consent shall be treated for all purposes as a
vote taken at a meeting of Shareholders.
11.5 Record Dates. For the purpose of determining the shareholders who
------------
are entitled to vote or act at any meeting or any adjournment thereof, or who
are entitled to receive payment of any dividend or of any other distribution,
the Trustees may from time to time fix a time, which shall be not more than 90
days before the date of any meeting of shareholders or the date for the payment
of any dividend or of any other distribution, as the record date for determining
the shareholders having the right to notice of and to vote at such meeting and
any adjournment thereof or the right to receive such dividend or distribution,
and in such case only shareholders of record on such record date shall have the
right notwithstanding any transfer of shares on the books of the Trust after the
record date; or without fixing such record date the Trustees may for any of such
purpose close the register or transfer books for all or any part of such period.
11.6 Proxy Instructions Transmitted by Telephonic or Electronic Means.
----------------------------------------------------------------
The placing of a Shareholder's name on a proxy pursuant to telephonic or
electronically transmitted instructions obtained pursuant to procedures
reasonably designed to verify that such
-7-
<PAGE>
instructions have been authorized by such Shareholder shall constitute execution
of such proxy by or on behalf of such Shareholder.
11.7 Derivative Claims. No Shareholder shall have the right to bring
-----------------
or maintain any court action, proceeding or claim on behalf of the Trust or any
series of shares of the Trust without first making demand on the Trustees
requesting the Trustees to bring or maintain such action, proceeding or claim.
Such demand shall be excused only when the plaintiff makes a specific showing
that irreparable injury to the Trust or series would otherwise result. Such
demand shall be mailed to the Secretary of the Trust at the Trust's principal
office and shall set forth in reasonable detail the nature of the proposed court
action, proceeding or claim and the essential facts relied upon by the
Shareholder to support the allegations made in the demand. The Trustees shall
consider such demand within 45 days of its receipt by the Trust. In their sole
discretion, the Trustees may submit the matter to a vote of Shareholders of the
Trust or series, as appropriate. Any decision by the Trustees to bring, maintain
or settle (or not to bring, maintain or settle) such court action, proceeding or
claim, or to submit the matter to a vote of Shareholders, shall be made by the
Trustees in their business judgment and shall be binding upon the Shareholders.
Any decision by the Trustees to bring or maintain a court action, proceeding or
suit on behalf of the Trust or a series shall be subject to the right of the
Shareholders under Article 11, Section 11.1 of these Bylaws to vote on whether
or not such court action, proceeding or suit should or should not be brought or
maintained.
ARTICLE 12
Indemnification
12.1 Rebuttable Presumption that Legal Fees may be Advanced. For
------------------------------------------------------
purposes of the determination or opinion referred to in clause (c) of the final
sentence of Article VIII, Section 1 of the Declaration of Trust, the majority of
disinterested Trustees acting on the matter or independent legal counsel, as the
case may be, shall afford the Covered Person (as defined in said Article VIII,
Section 1) a rebuttable presumption that the Covered Person has not engaged in
willful misfeasance, bad faith, gross negligence or reckless disregard of the
duties involved in the conduct of such Covered Person's office.
ARTICLE 13
Amendment to the Bylaws
13.1 General. These Bylaws may be amended or repealed, in whole or
-------
part, by a majority of the Trustees then in office at any meeting of the
Trustees, or by one or more writings signed by such a majority.
-8-
