Exhibit 4(a)

                                    EXHIBIT B

                      FORM OF INVESTMENT ADVISORY AGREEMENT

      AGREEMENT made this 1st day of January, 1981, by and between MERRILL LYNCH
MUNICIPAL BOND FUND, INC., a Maryland  corporation (the "Fund"),  and FUND ASSET
MANAGEMENT, INC., a Delaware corporation (the "Adviser"):

                              W I T N E S S E T H:

      WHEREAS,  the  Fund is  engaged  in  business  as a  diversified  open-end
management  investment  company and is registered  as such under the  Investment
Company Act of 1940 (the "Investment Company Act")

      WHEREAS,  the Fund is comprised  of. three  separate  Portfolios,  each of
which pursues its investment objective through separate investment policies;

      WHEREAS, the Adviser is engaged principally in rendering advisory services
and is registered as an investment adviser under the Investment  Advisers Act of
1940; and

      WHEREAS,  the Fund  desires  to retain the  Adviser  to render  investment
supervisory and corporate  administrative services to the Fund in the manner and
on the terms hereinafter set forth;

      NOW,  THEREFORE,  in  consideration  of the  premises  and  the  covenants
hereinafter contained, the Fund and the Adviser hereby agree as follows:

                                   ARTICLE 1.

                              Duties of the Adviser

      The Fund hereby  employs the Adviser to act as the  investment  adviser to
and manager of the Fund and to manage the  investment  and  reinvestment  of the
assets of each of its Portfolios  and to administer its affairs,  subject to the
supervision  of the Board of  Directors  of the Fund,  for the period and on the
terms and  conditions  set forth in this  Agreement.  The Adviser hereby accepts
such employment and agrees during such period, at its own expense, to render the
services  and to assume the  obligations  herein set forth for the  compensation
provided for herein.  The Adviser shall for all purposes  herein be deemed to be
an independent  contractor and shall,  unless  otherwise  expressly  provided or
authorized,  have no authority  to act for or  represent  the Fund in any way or
otherwise be deemed an agent of the Fund.

            (a) Investment Advisory Services. In acting as investment adviser to
the Fund,  the Adviser  shall  regularly  provide the Fund with such  investment
research,  advice and  supervision  as the latter may from time to time consider
necessary  for the  proper  supervision  of its  Portfolios  and  shall  furnish
continuously  an investment  program and shall  determine from time to time what
securities shall be purchased,  sold or exchanged and what portion of the assets
of each  Portfolio  shall  be held in the  various  securities  in  which it may
invest,   subject  always  to  the   restrictions  of  the  Fund's  Articles  of
Incorporation and By-Laws, as amended from time to

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time, the provisions of the Investment Company Act, and the statements  relating
to  the  Fund's  investment  objectives,   investment  policies  and  investment
restrictions as the same are set forth in the currently effective  prospectus of
the Fund under the Securities Act of 1933 (the "Prospectus").  The Adviser shall
also be  responsible  for all duties  arising in  connection  with any portfolio
insurance policies,  which the Insured Portfolio maintains.  Should the Board of
Directors of the Fund at any time, however,  make any definite  determination as
to investment policy and notify the Adviser thereof,  the Adviser shall be bound
by such  determination for the period, if any, specified in such notice or until
similarly notified that such  determination has been revoked.  The Adviser shall
take, on behalf of the Fund,  all actions which it deems  necessary to implement
the investment policies determined as provided above, and in particular to place
all orders for the purchase or sale of portfolio  securities  of each  Portfolio
with brokers or dealers selected by it. In connection with the selection of such
brokers or dealers  and the placing of such  orders,  the Adviser is directed at
all times to seek to obtain for the Fund the most favorable  execution and price
within the meaning of such terms as determined by the Board of Directors and set
forth in the Prospectus.  Subject to this  requirement and the provisions of the
Investment  Company  Act,  the  Securities  Exchange  Act  of  1934,  and  other
applicable  provisions of law, nothing shall prohibit the Adviser from selecting
brokers or dealers with which it or the Fund is affiliated.

            (b)  Administrative  Services.  In  addition to the  performance  of
investment  advisory  services,  the  Adviser  shall  perform or  supervise  the
performance of, administrative services in connection with the management of the
Fund and the Portfolios. In this connection, the Adviser agrees to (i) assist in
supervising all aspects of the Fund's operations,  including the coordination of
all matters  relating to the functions of the custodian,  transfer agent,  other
shareholder service agents, accountants,  attorneys and other parties performing
services or  operational  functions for the Fund,  (ii) provide the Fund, at the
Adviser's  expenses,   with  services  of  persons  competent  to  perform  such
administrative  and  clerical  functions  as are  necessary  in order to provide
effective  administration  of the  Fund,  including  duties in  connection  with
shareholder relations,  reports, redemption requests and account adjustments and
the  maintenance  of certain  books and records of the Fund,  (iii)  provide the
Fund, at the Adviser's expense,  with adequate office space and related services
necessary  for its  operations  as  contemplated  in this  Agreement,  and  (iv)
supervise and administer the operation of the Exchange  Privilege referred to in
the Prospectus.  The Fund  acknowledges  that the Adviser intends to arrange for
the provision of services and the  performance of functions  referred to in this
subsection  (b) by  Merrill  Lynch,  Pierce,  Fenner & Smith  Incorporated  (the
"Administrator") pursuant to an Administration Agreement between the Adviser and
the Administrator.

                                   ARTICLE 2.

                       Allocation of Charges and Expenses

            (a) The Adviser.  The Adviser  assumes and shall pay for maintaining
the staff and  personnel  and shall at its own expense  provide  the  equipment,
office space and  facilities,  necessary to perform its  obligations  under this
Agreement,  and shall pay all  compensation of officers of the Fund and the fees
of all directors of the Fund who are affiliated  persons of Merrill Lynch & Co.,
Inc. or its subsidiaries.


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<PAGE>

            (b) The Fund.  The Fund  assumes  and shall pay all  expenses of the
Fund, including,  without limitation,  organization costs,  insurance (including
portfolio insurance  maintained by the Insured Portfolio),  taxes,  expenses for
legal and auditing  services,  costs of printing  proxies,  stock  certificates,
shareholder  reports  and  prospectuses  (except  to  the  extent  paid  by  the
Distributor),   charges  of  the  Custodian  and  Transfer  Agent,  expenses  of
redemption  of shares,  Securities  and Exchange  Commission  fees,  expenses of
registering  the  shares  under  Federal  and state  securities  laws,  fees and
expenses of directors  who are not  affiliated  persons of Merrill  Lynch & Co.,
Inc. or its  subsidiaries,  accounting  and pricing costs  (including  the daily
calculation of net asset value), interest, brokerage costs, litigation and other
extraordinary or non-recurring  expenses, and other expenses properly payable by
the Fund.

                                   ARTICLE 3.

                           Compensation of the Adviser

            (a)  Investment  Advisory  Fee.  For  the  services  rendered,   the
facilities  furnished and expenses assumed by the Adviser, the Fund shall pay to
the Adviser at the end of each calendar month a fee based upon the average daily
value of the net  assets  of the  portfolios,  as  determined  and  computed  in
accordance with the ascription of the method of determination of net asset value
contained in the  Prospectus.  During any period when the  determination  of net
asset value is suspended  by the Board of  Directors of the Fund,  the net asset
value of a share as of the last business day prior to such suspension  shall for
this purpose be deemed to be the net asset value at the close of each succeeding
business day until it is again determined.

            The fee with  respect  to each  Portfolio  shall be at the rates set
forth  below.  These  rates are  subject to  reduction  to the  extent  that the
aggregate  of the  average  daily net  assets of the three  combined  Portfolios
exceeds $250  million.  [In  addition,  the fee payable by the Limited  Maturity
Portfolio is subject to further  reductions to the extent the combined assets of
the Portfolios  exceed $400 million and $550  million.] The reductions  shall be
applicable to each Portfolio regardless of size on a "uniform percentage" basis.
Determination  of the portion of the net assets of each  Portfolio  to which the
reduced  rates are  applicable  is made by  multiplying  the net  assets of that
Portfolio by "uniform percentages",  derived by dividing the amount by which the
combined assets of all Portfolios exceed the various  applicable  breakpoints by
such combined assets.

                                                    Rate of Advisory Fee
                                            ------------------------------------
           Aggregate of                                    High        Limited
     average daily net assets                Insured      Yield        Maturity
 of the three combined Portfolios           Portfolio    Portfolio    Portfolio
 --------------------------------           ---------    ---------    ---------

Not exceeding $250 million.................   0.40 %       0.50 %       0.40 %
In excess of $250 million but not
  exceeding $400 million ..................   0.375        0.475        0.375
In excess of $400 million but not
  exceeding $550 million ..................   0.375        0.475        0.350
In excess of $550 million..................   0.375        0.475        0.325


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<PAGE>

            (b) Expense Limitations.  In the event the operating expenses of any
Portfolio,  including the  investment  advisory fee applicable to such Portfolio
payable to the Adviser  pursuant to subsection  (a) hereof,  for any fiscal year
ending  on a date on which  this  Agreement  is in  effect  exceed  the  expense
limitations  applicable to that Portfolio  imposed by state  securities  laws or
regulations  thereunder,  as such limitations may be raised or lowered from time
to time, the Adviser shall reduce its  investment  advisory fee by the extent of
such  excess and, if  required  pursuant to any such laws or  regulations,  will
reimburse such Portfolio in the amount of such excess; provided, however, to the
extent  permitted by law,  there shall be excluded from such expenses the amount
of  any  interest,  taxes,  brokerage  commissions  and  extraordinary  expenses
(including but not limited to legal claims and liabilities and litigation  costs
and any  indemnification  related  thereto)  paid or  payable  by the  Fund  and
allocated to such Portfolio. Whenever the expenses of any Portfolio exceed a pro
rata portion of the applicable annual expense limitations, the estimated amounts
of reimbursement under such limitations shall be applicable as an offset against
the monthly payment of the advisory fee due to the Adviser.

                                   ARTICLE 4

                     Limitation of Liability of the Adviser

            The Adviser shall not be liable for any error of judgment or mistake
of law or for any loss  suffered by the Fund in connection  with any  investment
policy  or  the  purchase,   sale  or  redemption  of  any   securities  on  the
recommendation  of the Adviser.  Nothing herein  contained shall be construed to
protect the Adviser against any liability to the Fund or its security holders to
which the Adviser shall  otherwise be subject by reason of willful  misfeasance,
bad faith,  gross  negligence in the  performance of its duties on behalf of the
Fund,  reckless  disregard of the  Adviser's  obligations  and duties under this
Agreement or the violation of any applicable law.

                                   ARTICLE 5

                            Activities of the Adviser

            The  services  of the  Adviser  under this  Agreement  are not to be
deemed  exclusive,  and the Adviser shall be free to render similar  services to
others  so long  as its  services  hereunder  are not  impaired  thereby.  It is
understood that directors,  officers, employees and shareholders of the Fund are
or may become interested in the Adviser,  as directors,  officers,  employees or
shareholders   or  otherwise  and  that   directors,   officers,   employees  or
shareholders of the Adviser are or may become similarly  interested in the Fund,
and that the Adviser is or may become  interested in the Fund as  shareholder or
otherwise.

                                   ARTICLE 6

                   Duration and Termination of this Agreement

            This  Agreement  shall  become  effective as of the date first above
written and shall remain in force until  December 31, 1981 and  thereafter,  but
only so long as such  continuance is specifically  approved at least annually by
(i) the Board of  Directors  of the Fund,  or by the vote of a  majority  of the
outstanding shares of the Fund including a majority of the outstanding shares of


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each  Portfolio,  and (ii) a majority of those  directors who are not parties to
this  Agreement  or  interested  persons  of any such  party cast in person at a
meeting called for the purpose of voting on such approval.

            This Agreement may be terminated at any time, without the payment of
any  penalty,  by the Board of Directors of the Fund or by vote of a majority of
the  outstanding  shares of the Fund,  or by the Adviser on sixty days'  written
notice to the other party. This Agreement shall  automatically  terminate in the
event of its assignment.

                                    ARTICLE 7

                                   Definitions

            The terms "assignment", "affiliated person" and "interested person",
when used in this Agreement, shall have the respective meanings specified in the
Investment  Company  Act.  As  used  with  respect  to  the  Fund  or any of its
Portfolios,  the term "majority of the  outstanding  shares" means the lesser of
(i) 67% of the  shares  represented  at a meeting  at which more than 50% of the
outstanding  shares  are  represented  or (ii) more than 50% of the  outstanding
shares.

                                   ARTICLE 8

                          Amendments of this Agreement

            This  Agreement may be amended by the parties only if such amendment
is  specifically  approved by (i) the Board of Directors of the Fund,  or by the
vote of a majority of  outstanding  shares of the Fund,  including a majority of
the outstanding shares of each Portfolio, and (ii) a majority of those directors
of the Fund who are not parties to this  Agreement or interested  persons of any
such party cast in person at a meeting  called for the purpose of voting on such
approval.

                                   ARTICLE 9

                                  Governing Law

            The provisions of this Agreement  shall be construed and interpreted
in  accordance  with the laws of the  State of New York as at the time in effect
and the applicable  provisions of the Investment Company Act. To the extent that
the applicable  law of the State of New York, or any of the  provisions  herein,
conflict  with the  applicable  provisions  of the  Investment  Company Act, the
latter shall control.


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<PAGE>

            IN WITNESS WHEREOF,  the parties hereto have executed this Agreement
as of the day and year first above written.

                                        MERRILL LYNCH MUNICIPAL BOND FUND, INC.


                                        By: ____________________________________
Attest:


_____________________________________
Secretary
                                        FUND ASSET MANAGEMENT, INC.


                                        By:_____________________________________
Attest:


_____________________________________
Secretary


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