Exhibit 10(b)






                            MERRIMAC INDUSTRIES, INC.

                         375,000 SHARES OF COMMON STOCK


                          REGISTRATION RIGHTS AGREEMENT

                                  April 7, 2000


   <PAGE>




                            MERRIMAC INDUSTRIES, INC.

                          REGISTRATION RIGHTS AGREEMENT

     This  Registration  Rights Agreement (the  "Agreement") is made as of April
__, 2000, by and between  Merrimac  Industries,  Inc., a New Jersey  corporation
(the  "Company"),  and  Ericsson  Holding  International,  B.V.,  a  Netherlands
corporation (the "Purchaser")

                                    RECITALS

     The Company and the  Purchaser  have entered into a letter  agreement  (the
"Purchase  Agreement"),  dated  as of the date  hereof,  pursuant  to which  the
Company  sold to the  Purchaser  and the  Purchaser  purchased  from the Company
375,000  shares of the  Company's  Common Stock (the  "Shares").  A condition to
Purchaser's  obligations under the Purchase  Agreement is that the Company enter
into this  Agreement in order to provide the  Purchaser  with certain  rights to
register  the Shares.  The Company  desires to comply with its  covenants in the
Purchase  Agreement and to induce the Purchaser to purchase the Shares  pursuant
to the  Purchase  Agreement  by agreeing to the terms and  conditions  set forth
herein.

                                    AGREEMENT

         The parties hereby agree as follows:


     1. Definitions. Capitalized terms used herein without definition shall have
their respective meanings set forth in or pursuant to the Purchase Agreement. As
used in this Agreement,  the following  capitalized defined terms shall have the
following meanings:

     "Act" or "Securities Act" means the United States Securities Act of 1933,
      as amended.

     "Affiliate" of any specified person means any other person which,  directly
or  indirectly,  is in control of, is controlled  by, or is under common control
with such specified person. For purposes of this definition, control of a person
means the power,  direct or  indirect,  to direct or cause the  direction of the
management and policies of such person whether by contract or otherwise; and the
terms "controlling" and "controlled" have meanings correlative to the foregoing.

     "Common Stock" means the Company's Common Stock, par value $0.50 per share.

     "Exchange Act" means the United States Securities  Exchange Act of 1934, as
amended.

     "Form S-3" means such form under the Act as in effect on the date hereof or
any successor form under the Act.

     "Holder"  means  the  Purchaser  and any  permitted  transferees  under the
Purchase Agreement that hold Shares.


                                       -2-
   <PAGE>

     "Person"  shall  mean an  individual,  partnership,  corporation,  trust or
unincorporated organization,  or a government or agency or political subdivision
thereof.

     "Registrable  Securities"  means all or any  portion of the Shares or other
securities  of the Company  issued to Purchaser in connection  with  Purchaser's
ownership of the Shares;  provided,  that such Shares and other  securities will
cease  to  be  Registrable  Securities  when  and  to  the  extent  that  (a)  a
Registration  Statement  covering the  Registrable  Securities has been declared
effective  under the Securities  Act and the  Registrable  Securities  have been
disposed  of  pursuant  to  such  effective  Registration  Statement,   (b)  the
Registrable  Securities are  distributed to the public  pursuant to Rule 144 (or
any  successor  provision  then in force)  under the  Securities  Act,  (c) such
Registrable  Securities  are no longer  held by a Holder or (d) the  Registrable
Securities have ceased to be outstanding.

     "Registration  Statement"  means a  registration  statement  of the Company
under the  Securities  Act on any form (to be selected by the Company) for which
the Company then  qualifies and which permits the sale  thereunder of the number
and type of  Registrable  Securities  (and any other  securities of the Company)
requested by Holder pursuant to this Agreement to be included therein.  The term
Registration  Statement shall also include all exhibits and financial statements
and  schedules  and  documents  incorporated  by reference in such  Registration
Statement when it becomes effective under the Securities Act, and in the case of
the  references  to the  Registration  Statement as of a date  subsequent to the
effective date, as amended or supplemented as of such date.

         "SEC" means the Securities and Exchange Commission.



                             2. Registration Rights.


                    2.1 Purchaser's Request for Registration.

     (a) If the Company shall receive at any time after two years after the date
hereof,  a written request from the Holders that the Company file a Registration
Statement  covering the registration of at least the lesser of (i) fifty percent
(50%)  of the  Registrable  Securities  then  outstanding  or  (ii)  Registrable
Securities  having an anticipated  aggregate  public  offering price of at least
$1.0  million,  then the Company  shall,  within twenty (20) days of the receipt
thereof,  give written notice of such request to all Holders, and shall, subject
to the limitations of subsection 2.2(b),  use its best efforts to effect as soon
as practicable,  and in any event within ninety (90) days of the receipt of such
request, the registration under the Act of all Registrable  Securities which the
Holders request to be registered  within twenty (20) days of the mailing of such
notice by the Company in accordance with Section 4.5.

     (b)  If  the  Holders   initiating  the  registration   request   hereunder
("Initiating  Holders") intend to distribute the Registrable  Securities covered
by their request by means of an  underwriting,  they shall so advise the Company
as a part of their  request made pursuant to this  Section 2.1,  and the Company
shall  include  such   information  in  the  written   notice   referred  to  in
subsection 2.1(a). The underwriter will be selected by the Company and shall be

                                       -3-

   <PAGE>

 reasonably  acceptable to a majority in interest of the Initiating  Holders. In
such event,  the right of any Holder to include his  Registrable  Securities  in
such registration shall be conditioned upon such Holder's  participation in such
underwriting  and the inclusion of such Holder's  Registrable  Securities in the
underwriting  (unless otherwise mutually agreed by a majority in interest of the
Initiating  Holders and such Holder) to the extent provided herein.  All Holders
proposing  to  distribute  their  securities  through  such  underwriting  shall
(together  with  the  Company  as  provided  in  subsection 2.8  enter  into  an
underwriting  agreement in customary form with the  underwriter or  underwriters
selected  for such  underwriting.  Notwithstanding  any other  provision of this
Section 2.1,  if the  underwriter  advises the Company in writing that marketing
factors  require a limitation of the number of shares to be  underwritten,  then
the Company shall so advise all Holders of  Registrable  Securities  which would
otherwise  be  underwritten  pursuant  hereto,  and  the  number  of  shares  of
Registrable  Securities  that  may be  included  in the  underwriting  shall  be
allocated  among all Holders  thereof,  including  the  Initiating  Holders,  in
proportion (as nearly as practicable) to the amount of Registrable Securities of
the Company owned by each Holder;  provided,  however, that the number of shares
of  Registrable  Securities  to be  included in such  underwriting  shall not be
reduced  unless  all other  securities  are  first  entirely  excluded  from the
underwriting.  Any  Registrable  Securities  excluded  and  withdrawn  from such
underwriting shall be withdrawn from the registration.

     (c) Notwithstanding the foregoing,  if the Company shall furnish to Holders
requesting a Registration Statement pursuant to this Section 2.1,  a certificate
signed by the President of the Company  stating that in the good faith  judgment
of the Board of Directors of the Company,  it would be seriously  detrimental to
the Company and its shareholders for such Registration Statement to be filed and
it is therefore  essential to defer the filing of such  Registration  Statement,
the  Company  shall have the right to defer such filing for a period of not more
than sixty (60) days after  receipt of the  request of the  Initiating  Holders;
provided, however, that the Company may not utilize this right more than once in
any twelve-month period.

     (d) In addition,  the Company shall not be obligated to effect,  or to take
any action to effect, any registration pursuant to this Section 2.1:

     (i) After the Company has effected two (2)  registrations  pursuant to this
Section 2.1 and such registrations have been declared or ordered effective;

     (ii) If the Company has effected a  registration  within the 90-day  period
next preceding such request; or

     (iii) During the period starting with the date sixty (60) days prior to the
Company's good faith estimate of the date of filing of, and ending on a date one
hundred eighty (180) days after the effective date of, a registration subject to
Section 2.2 hereof;  provided  that the  Company is actively  employing  in good
faith all  reasonable  efforts to cause such  Registration  Statement  to become
effective.


                                       -4-

   <PAGE>

     (c)  Notwithstanding  anything  to the  contrary  contained  in  any  other
provision  of this  Agreement,  the  Company  shall not be  required to effect a
registration  under the Act of an  offering  on a delayed  or  continuous  basis
pursuant to Rule 415 (or any successor provision then in force) under the Act (a
"Shelf Registration") or maintain the effectiveness of a registration  statement
to effect a Shelf  Registration  at the  request of the Holder  pursuant to this
Section 2.1.

                            2.2 Company Registration.

     (a) If (but  without  any  obligation  to do so) the  Company  proposes  to
register (including for this purpose a registration  effected by the Company for
shareholders  other  than  the  Holders)  any  of its  stock  under  the  Act in
connection with the public  offering of such  securities  solely for cash (other
than a registration relating solely to the sale of securities to participants in
a Company stock plan or a transaction  covered by Rule 145  under the Act),  the
Company  shall,  at such time,  promptly give each Holder written notice of such
registration.  Upon the written  request of each Holder given within twenty (20)
days after mailing of such notice by the Company in accordance with Section 4.5,
the  Company  shall,  subject  to the  provisions  of  Section 2.3,  cause to be
registered under the Act all of the Registrable Securities that each such Holder
has requested to be  registered  (subject,  however,  to reduction in accordance
with Section 2.2(b)).  If a Holder decides not to include all of its Registrable
Securities in any registration  statement thereafter filed by the Company,  such
Holder shall nevertheless  continue to have the right to include any Registrable
Securities  in any  subsequent  registration  statements  as may be filed by the
Company  with respect to  offerings  of its  securities,  all upon the terms and
conditions set forth herein.

     (b) In the event the Holder desires to participate in an offering  pursuant
to  Section  2.2(a),  the  Holder  may  include  Registrable  Securities  in any
Registration  Statement  relating  to  such  offering  to the  extent  that  the
inclusion of such Registrable Securities will not reduce the number of shares of
Common  Stock to be offered  and sold  pursuant  thereto by the  Company  demand
registration  rights  with  respect  to  such  offering.  If the  lead  managing
underwriter  selected by the Company for an  underwritten  offering  pursuant to
Section 2.2(a)  determines  that marketing  factors  require a limitation on the
number of shares of Common Stock to be offered and sold by the  shareholders  of
the Company in such  offering,  there will be included in the offering only that
number of shares of Common Stock,  if any,  that such lead managing  underwriter
determines  will not  jeopardize  the  success of the  offering of all shares of
Common Stock that the Company desires to sell for its own account. In such event
and provided the  managing  underwriter  has so notified the Company in writing,
the number of shares of Common Stock to be offered and sold by the  shareholders
of the Company,  including the Holder,  desiring to participate in such offering
will be allocated  among such holders of shares of Common Stock first,  pro rata
pro rata  among the  Holders  and  second,  among  securities  to be  registered
pursuant to demand registration rights held by Persons other than the Holders.

                         2.3 Obligations of the Company.

     Whenever  required under this Section 2 to effect the  registration  of any
Registrable  Securities,  the Company  shall,  as  expeditiously  as  reasonably
practicable:

                                       -5-

   <PAGE>


     (a) Subject to Sections 2.1(c) and 2.1(d),  prepare and file with the SEC a
Registration Statement on any form for which the Company then qualifies or which
counsel  for  the  Company  deems  appropriate,  which  form is  subject  to the
reasonable approval of the Holders  participating in the offering and which form
is available for the sale of the  Registrable  Securities in accordance with the
intended methods of distribution thereof, and use its best efforts to cause such
Registration Statement to become effective; and, upon the request of any Holder,
keep such Registration  Statement  effective for up to ninety (90) days or until
all Holders have completed the distribution relating thereto; provided, however,
that such ninety (90) day period shall be extended for a period of time equal to
the period the Holders  refrain  from  selling any  securities  included in such
registration  at the written  request of the Company in accordance  with Section
2.4 or an underwriter.

     (b) Prepare and file with the SEC such  amendments and  supplements to such
Registration   Statement  and  the  prospectus  used  in  connection  with  such
Registration  Statement as may be necessary to comply with the provisions of the
Act  with  respect  to  the  disposition  of  all  securities  covered  by  such
registration statement.

     (c)  Furnish  to the  Holders  such  numbers  of  copies  of a  prospectus,
including a preliminary  prospectus,  in conformity with the requirements of the
Act,  and such  other  documents  as they  may  reasonably  request  in order to
facilitate the disposition of Registrable Securities owned by them.

     (d) Use its best efforts to register and qualify the securities  covered by
such Registration Statement under such other securities or blue sky laws of such
jurisdictions as shall be reasonably requested by the Holders, provided that the
Company shall not be required in connection  therewith or as a condition thereto
to qualify to do business or to file a general  consent to service of process in
any such states or jurisdictions.

     (e) In the  event  of any  underwritten  public  offering,  enter  into and
perform its obligations under an underwriting  agreement, in usual and customary
form, with the managing underwriter of such offering.  Each Holder participating
in such  underwriting  shall also enter into and perform its  obligations  under
such an agreement.

     (f)  Notify  each  Holder  of  Registrable   Securities   covered  by  such
Registration  Statement  at any  time  when a  prospectus  relating  thereto  is
required to be delivered under the Act of the happening of any event as a result
of which the  prospectus  included in such  Registration  Statement,  as then in
effect,  includes  an untrue  statement  of a material  fact or omits to state a
material fact required to be stated  therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

     (g) Cause all such Registrable Securities registered hereunder to be listed
on each securities  exchange on which similar  securities  issued by the Company
are then listed.

                                       -6-

   <PAGE>


     (h) Provide a transfer agent and registrar for all  Registrable  Securities
registered  pursuant  hereunder  and a CUSIP  number  for all  such  Registrable
Securities, in each case not later than the effective date of such registration.

                 2.4 Delay of Effective Registration Statement.

     Upon receipt of written  notice from the Company as provided  herein of the
happening of any event of the kind described in Section 2.3(f), the Holders will
forthwith  discontinue  disposition  of Registrable  Securities  pursuant to the
prospectus or Registration  Statement covering such Registrable Securities until
the Holders' receipt of copies of the supplemented or amended prospectus (at the
Company's expense), and, if so directed by the Company, the Holders will deliver
to the Company (at the Company's expense) all copies,  other than permanent file
copies  then  in  the  Holders'  possession  of  the  prospectus  covering  such
Registrable Securities current at the time of receipt of such notice.

                            2.5 Furnish Information.

     It shall be a condition precedent to the obligations of the Company to take
any action pursuant to this Section 2 with respect to the Registrable Securities
of any  selling  Holder  that such  Holder  shall  furnish to the  Company  such
information  regarding  itself,  the Registrable  Securities held by it, and the
intended method of disposition of such securities as shall be required to effect
the registration of such Holder's Registrable Securities.

                      2.6 Expenses of Demand Registration.

     (a) Except as provided  in Section  2.6(b),  all  expenses,  including  all
registration,  filing and qualification fees,  printers' and accounting fees and
fees and disbursements of counsel for the Company, shall be borne by the Company
in  connection  with the  registration  of  Registrable  Securities  pursuant to
Section 2.1;  provided,  however,  that the Company shall not be required to pay
for any expenses of any registration proceeding begun pursuant to Section 2.1 if
the registration request is subsequently withdrawn at the request of the Holders
(in which case the Holders shall bear such  out-of-pocket  expenses  incurred in
the preparation,  filing and processing of the Registration  Statement),  unless
the Holders agree to forfeit their right to one demand registration  pursuant to
Section 2.1.

     (b) The  Holders  will  pay any fees or  disbursements  of  counsel  to the
Holders and all  underwriting  discounts and  commissions and transfer taxes, if
any, and other fees,  costs and expenses of the Holders  relating to the sale or
disposition of the Registrable Securities pursuant to a Registration Statement.

                      2.7 Expenses of Company Registration.

     (a) Except as provided in Section  2.6(b),  the Company  shall bear and pay
all  expenses   incurred  in  connection  with  any   registration,   filing  or
qualification  of  Registrable  Securities  with  respect  to the  registrations
pursuant to Section 2.2  for the Holders,  including  (without  limitation)  all
registration,  filing,  and  qualification  fees,  printers' and accounting fees
relating or  apportionable  thereto,  but excluding  underwriting  discounts and
commissions  relating to the Registrable  Securities and the reasonable fees and
disbursements of counsel for the selling Holders.

                                       -7-

   <PAGE>


     (b) The  Holders  will  pay any fees or  disbursements  of  counsel  to the
Holders and all  underwriting  discounts and  commissions and transfer taxes, if
any, and other fees,  costs and  expenses of the Holder  relating to the sale or
disposition of the Registrable Securities pursuant to a Registration  Statement;
provided  however,  that the  Holders  shall  have no  obligation  to pay  their
respective pro rata share of the incremental  registration fee payable under the
Act or any blue sky fees and expenses, if applicable.

                         2.8 Underwriting Requirements.

     In connection with any offering  involving an underwriting of shares of the
Company's  capital stock, the Company shall not be required under Section 2.1 or
Section  2.2 to include  any of the  Holders'  securities  in such  underwriting
unless they  accept the terms of the  underwriting  as agreed  upon  between the
Company and the  underwriters  selected by it (or by other  persons  entitled to
select the  underwriters),  and then only in such  quantity as the  underwriters
determine  in their  sole  discretion  will not  jeopardize  the  success of the
offering  by  the  Company.  If  the  total  amount  of  securities,   including
Registrable  Securities,  requested  by  shareholders  to be  included  in  such
offering  exceeds the amount of  securities  sold other than by the Company that
the  underwriters  determine in their sole  discretion  is  compatible  with the
success of the  offering,  then the Company  shall be required to include in the
offering only that number of such securities,  including Registrable Securities,
which the  underwriters  determine in their sole  discretion will not jeopardize
the success of the offering (the  securities so included to be  apportioned  pro
rata among the selling shareholders  according to the total amount of securities
entitled to be included  therein  owned by each selling  shareholder)  provided,
however,  that the number of shares of Registrable  Securities to be included in
such underwriting  shall not be reduced unless all securities offered by Persons
other than the Company are first entirely  excluded from the  underwriting.  For
purposes  of the  preceding  parenthetical  concerning  apportionment,  for  any
selling  shareholder which is a holder of Registrable  Securities and which is a
partnership or corporation,  the partners,  retired  partners,  shareholders and
affiliated partnerships of such holder, or the estates and family members of any
such partners and retired  partners and any trusts for the benefit of any of the
foregoing persons shall be deemed to be a single "selling  shareholder," and any
pro-rata  reduction with respect to such "selling  shareholders"  shall be based
upon the aggregate  amount of shares carrying  registration  rights owned by all
entities and individuals  included in such "selling  shareholder," as defined in
this sentence.

                           2.9 Delay of Registration.

     No Holder shall have any right to obtain or seek an injunction  restraining
or otherwise  delaying any such  registration  as the result of any  controversy
that might arise with respect to the  interpretation  or  implementation of this
Section 2.

                              2.10 Indemnification.

     In the event any  Registrable  Securities  are  included in a  Registration
Statement under this Section 2:

     (a) To the extent  permitted by law, the Company  will  indemnify  and hold
harmless each Holder,  any  underwriter  (as defined in the Act) for such Holder
and each  person,  if any, who controls  such Holder or  underwriter  within the
meaning of the Act or the Exchange Act, against any losses, claims,  damages, or
liabilities  (joint or several) to which they may become  subject under the Act,
the Exchange Act or other federal or state law, insofar as such losses, claims,


                                       -8-

   <PAGE>

damages,  or  liabilities  (or actions in respect  thereof)  arise out of or are
based  upon  any  of  the   following   statements,   omissions  or   violations
(collectively  a  "Violation"):  (i) any  untrue  statement  or  alleged  untrue
statement of a material fact contained in such Registration Statement, including
any  preliminary  prospectus  or  final  prospectus  contained  therein  or  any
amendments or  supplements  thereto,  (ii) the  omission or alleged  omission to
state  therein a material fact  required to be stated  therein,  or necessary to
make the statements  therein not misleading,  or (iii) any  violation or alleged
violation by the Company of the Act, the Exchange Act, any state  securities law
or any rule or  regulation  promulgated  under the Act,  the Exchange Act or any
state securities law; and the Company will pay to each such Holder,  underwriter
or  controlling  person,  as incurred,  any legal or other  expenses  reasonably
incurred by them in connection  with  investigating  or defending any such loss,
claim,  damage,  liability,  or action;  provided,  however,  that the indemnity
agreement contained in this  subsection 2.10(a)  shall not apply to amounts paid
in  settlement of any such loss,  claim,  damage,  liability,  or action if such
settlement is effected  without the consent of the Company  (which consent shall
not be unreasonably withheld),  nor shall the Company be liable in any such case
for any such loss,  claim,  damage,  liability,  or action to the extent that it
arises out of or is based upon a Violation which occurs (x) in reliance upon and
in conformity with written information furnished expressly for use in connection
with such  registration by any such Holder,  underwriter or controlling  person,
(y) results  from such Holder's  failure to deliver a copy of the  prospectus or
any  supplements  thereto  after the  Company has  furnished  such Holder with a
sufficient  number of copies of same, or (z) results from such Holder's delivery
of  prospectuses  after the  Company  has  notified  such  Holder in  writing to
discontinue delivery of prospectuses.

     (b) To the extent  permitted by law, each selling Holder will indemnify and
hold harmless the Company,  each of its directors,  each of its officers who has
signed the Registration Statement, each person, if any, who controls the Company
within  the  meaning  of the Act,  any  underwriter,  any other  Holder  selling
securities in such registration statement and any controlling person of any such
underwriter or other Holder, against any losses, claims, damages, or liabilities
(joint or several)  to which any of the  foregoing  persons may become  subject,
under the Act, the Exchange Act or other  federal or state law,  insofar as such
losses,  claims,  damages,  or liabilities (or actions in respect thereto) arise
out of or are based upon any Violation,  in each case to the extent (and only to
the extent) that such Violation  occurs in reliance upon and in conformity  with
written  information  furnished by such Holder  expressly  for use in connection
with such registration; and each such Holder will pay, as incurred, any legal or
other  expenses  reasonably  incurred by any person  intended to be  indemnified
pursuant  to  this  subsection 2.10(b),  in  connection  with  investigating  or
defending any such loss, claim, damage, liability, or action; provided, however,
that the  indemnity  agreement  contained in this  subsection 2.10(b)  shall not
apply to amounts paid in settlement of any such loss, claim,  damage,  liability
or action if such  settlement  is  effected  without  the consent of the Holder,
which consent shall not be unreasonably  withheld;  provided,  that, in no event
shall any indemnity under this  subsection 2.10(b)  exceed the net proceeds from
the offering received by such Holder,  except in the case of willful  misconduct
by such Holder.

                                       -9-

   <PAGE>

     (c) Promptly after receipt by an indemnified  party under this Section 2.10
of notice of the commencement of any action (including any governmental action),
such indemnified party will, if a claim in respect thereof is to be made against
any  indemnifying  party under this  Section 2.10,  deliver to the  indemnifying
party a written notice of the commencement  thereof and the  indemnifying  party
shall have the right to  participate  in,  and,  to the extent the  indemnifying
party so desires,  jointly with any other  indemnifying party similarly noticed,
to assume the defense thereof with counsel mutually satisfactory to the parties;
provided,   however,   that  an  indemnified  party  (together  with  all  other
indemnified  parties which may be represented  without  conflict by one counsel)
shall have the right to retain one separate  counsel,  with the reasonable  fees
and expenses to be paid by the  indemnifying  party, if  representation  of such
indemnified  party by the counsel  retained by the  indemnifying  party would be
inappropriate  due to actual  or  potential  differing  interests  between  such
indemnified  party and any  other  party  represented  by such  counsel  in such
proceeding.  The failure to deliver  written  notice to the  indemnifying  party
within a reasonable time of the  commencement of any such action,  if materially
prejudicial   to  its  ability  to  defend  such  action,   shall  relieve  such
indemnifying  party  of  any  liability  to the  indemnified  party  under  this
Section 2.10,  but the omission so to deliver written notice to the indemnifying
party will not relieve it of any liability  that it may have to any  indemnified
party otherwise than under this Section 2.10.

     (d) If the  indemnification  provided for in this Section 2.10 is held by a
court of competent  jurisdiction to be unavailable to an indemnified  party with
respect to any loss,  liability,  claim, damage, or expense referred to therein,
then the  indemnifying  party, in lieu of indemnifying  such  indemnified  party
hereunder,  shall  contribute to the amount paid or payable by such  indemnified
party as a result of such loss,  liability,  claim,  damage,  or expense in such
proportion as is appropriate  to reflect the relative fault of the  indemnifying
party on the one hand and of the  indemnified  party on the other in  connection
with the statements or omissions that resulted in such loss,  liability,  claim,
damage,  or  expense  as well as any other  relevant  equitable  considerations;
provided,  that,  in no event  shall any  contribution  by a Holder  under  this
Subsection 2.10(d)  exceed the net proceeds  from the offering  received by such
Holder,  except in the case of willful  misconduct by such Holder.  The relative
fault of the indemnifying party and of the indemnified party shall be determined
by  reference  to,  among other  things,  whether  the untrue or alleged  untrue
statement of a material fact or the omission to state a material fact relates to
information  supplied by the indemnifying  party or by the indemnified party and
the parties' relative intent, knowledge, access to information,  and opportunity
to correct or prevent such statement or omission.

     (e)  Notwithstanding  the  foregoing,  to the extent that the provisions on
indemnification and contribution contained in the underwriting agreement entered
into in connection  with the  underwritten  public offering are in conflict with
the foregoing  provisions,  the provisions in the  underwriting  agreement shall
control.

     (f) The  obligations  of the Company and  Holders  under this  Section 2.10
shall  survive the  completion  of any offering of  Registrable  Securities in a
registration statement under this Section 2, and otherwise.

               2.10 Reports Under Securities Exchange Act of 1934.

     With a view to making  available  to the Holders  the  benefits of Rule 144
promulgated  under the Act and any other rule or  regulation of the SEC that may
at any time  permit a Holder to sell  securities  of the  Company  to the public
without  registration  or pursuant to a  registration  on Form S-3,  the Company
agrees to:

                                      -10-

   <PAGE>

     (a)  make  and keep  public  information  available,  as  those  terms  are
understood  and defined in SEC  Rule 144,  at all times  after  ninety (90) days
after  the  effective  date of the  first  registration  statement  filed by the
Company for the offering of its  securities to the general public so long as the
Company remains subject to the periodic reporting requirements under Sections 13
or 15(d) of the Exchange Act;

     (b) use its  best  efforts  to file  with the SEC in a  timely  manner  all
reports  and  other  documents  required  of the  Company  under the Act and the
Exchange  Act (at  any  time  after  it has  become  subject  to such  reporting
requirements); and

     (c)  furnish  to any  Holder,  so long as the Holder  owns any  Registrable
Securities,  forthwith upon request (i) a written  statement by the Company that
it has complied  with the  reporting  requirements  of SEC Rule 144 (at any time
after  ninety  (90) days  after  the  effective  date of the first  registration
statement filed by the Company), the Act and the Exchange Act (at any time after
it has become subject to such reporting  requirements),  (ii) a copy of the most
recent  annual or  quarterly  report of the Company  and such other  reports and
documents so filed by the Company,  and (iii) such  other  information as may be
reasonably requested in availing any Holder of any rule or regulation of the SEC
which  permits  the  selling  of any such  securities  without  registration  or
pursuant to such form.

                     2.12 Assignment of Registration Rights.

     The rights to cause the Company to register Registrable Securities pursuant
to this  Section 2 may be assigned  (but only with all related  obligations)  to
permitted transferees.

                        2.13 Market Stand-Off Agreement.

     Each Holder hereby  agrees that,  during the period of duration (up to, but
not exceeding,  180 days)  specified by the Company and an underwriter of Common
Stock  or other  securities  of the  Company,  following  the date of the  final
prospectus  distributed  in  connection  with a  Registration  Statement  of the
Company  filed  under the Act,  it shall  not,  to the extent  requested  by the
Company  and such  underwriter,  directly  or  indirectly  sell,  offer to sell,
contract to sell  (including,  without  limitation,  any short sale),  grant any
option to purchase or otherwise transfer or dispose of (other than to donees who
agree to be  similarly  bound) any  securities  of the Company held by it at any
time during such period except Common Stock purchased in the public offering and
Common Stock purchased in an open market transaction;  provided,  however,  that
all officers and directors of the Company enter into similar agreements.

     In  order to  enforce  the  foregoing  covenant,  the  Company  may  impose
stop-transfer  instructions  with respect to the Registrable  Securities of each
Holder  (and the  shares or  securities  of every  other  person  subject to the
foregoing  restriction)  until the end of such  period,  and each Holder  agrees
that,  if so  requested,  such  Holder  will  execute an  agreement  in the form
provided by the underwriter  containing  terms which are essentially  consistent
with the provisions of this Section 2.13.

                                      -11-

   <PAGE>

     Notwithstanding  the foregoing,  the obligations  described in this Section
2.13 shall not apply to a registration relating solely to employee benefit plans
on Form S-1 or Form S-8 or similar forms which may be promulgated in the future,
or a registration  relating solely to an SEC Rule 145 transaction on Form S-4 or
similar forms which may be promulgated in the future.

                    2.14 Termination of Registration Rights.

     No Holder  shall be  entitled to exercise  any right  provided  for in this
Section 2 after such time as Rule 144 or another similar exemption under the Act
is available for the sale of all of such Holder's Registrable  Securities during
a three (3)-month period.

                2.15 Limitation of Subsequent Registration Rights

     From and after the date of this Agreement,  the Company shall not,  without
the written consent of the Holders of a majority of the outstanding  Registrable
Securities,  enter into any agreement with any holder or  prospective  holder of
any  securities  of the Company  which  would  allow such holder or  prospective
holder to include  such  securities  in any  registration  filed by the Company,
unless under the terms of such agreement,  such holder or prospective holder may
include  such  securities  in an such  registration  only to the extent that the
inclusion of its securities will not reduce the amount of Registrable Securities
of the Holders which is included.

                                3. Miscellaneous.

                           3.1 Successors and Assigns.

     Except as otherwise provided herein or in the Purchase Agreement, the terms
and  conditions of this  Agreement  shall inure to the benefit of and be binding
upon the respective  successors and permitted  assigns of the parties  provided,
however,  that none of the rights,  interests or obligations  hereunder shall be
assigned (by operation of law or  otherwise)  by any of the parties  without the
prior written consent of the other party. Nothing in this Agreement,  express or
implied,  is intended to confer upon any party other than the parties  hereto or
their  respective  successors  and  permitted  assigns  any  rights,   remedies,
obligations,  or  liabilities  under or by reason of this  Agreement,  except as
expressly provided in this Agreement.

                               3.2 Governing Law.

     This  Agreement  and all acts and  transactions  pursuant  hereto  shall be
governed,  construed and interpreted in accordance with the laws of the State of
New York, without giving effect to principles of conflicts of laws.

                                3.3 Counterparts.

     This Agreement may be executed in two or more  counterparts,  each of which
shall be deemed an original,  but all of which together shall constitute one and
the same instrument.

                            3.4 Titles and Subtitles.

     The titles and subtitles  used in this  Agreement are used for  convenience
only and are not to be considered in construing or interpreting this Agreement.

                                  3.5 Notices.

     Unless  otherwise  provided,  any  notice  required  or  permitted  by this
Agreement shall be in writing and shall be deemed sufficient upon delivery, when
delivered  personally  or by  overnight  courier or sent by  telegram or fax, or
forty-eight  (48) hours after being  deposited in the U.S. mail, as certified or
registered mail, with postage prepaid, and addressed to the party to be notified
at  such  party's  address  as  set  forth  in  the  Purchase  Agreement  or  as
subsequently modified by written notice.

                                      -12-


   <PAGE>

                           3.6 Amendments and Waivers.

     Any term of this Agreement may be amended and the observance of any term of
this Agreement may be waived (either  generally or in a particular  instance and
either  retroactively  or  prospectively),  only with the written consent of the
Company  and the  holders  of a  majority  of the  Registrable  Securities  then
outstanding.  Any amendment or waiver effected in accordance with this paragraph
shall  be  binding  upon  each  holder  of  any   Registrable   Securities  then
outstanding,  each future  holder of all such  Registrable  Securities,  and the
Company.

                                3.7 Severability.

     If one or more  provisions of this  Agreement are held to be  unenforceable
under  applicable  law, the parties agree to renegotiate  such provision in good
faith.  In the event that the  parties  cannot  reach a mutually  agreeable  and
enforceable  replacement  for such provision,  then (x) such  provision shall be
excluded  from  this  Agreement,  (y) the  balance  of the  Agreement  shall  be
interpreted  as if such  provision  were so excluded and (z) the  balance of the
Agreement shall be enforceable in accordance with its terms.

                3.8 Consent to Jurisdiction; Service of Process.

     To the fullest extent permitted by applicable law, each party hereto hereby
irrevocably  and  unconditionally  waives  all  rights to a trial by jury in any
suit, action or proceeding.

                                      -13-


   <PAGE>










     The parties have executed this Registration Rights Agreement as of the date
first written above.

                                   MERRIMAC INDUSTRIES, INC.

                                   By:      /s/  Mason N. Carter
                                   Name:    Mason N. Carter
                                   Title:   Chairman and Chief Executive Officer

                                   ERICSSON HOLDING INTERNATIONAL, B.V.

                                   By:      /s/  Thomas Moller_________
                                   Name:    Thomas Moller

                            [Signature Page to Registration Rights Agreement]


                                      -14-