EXHIBIT  B   
- ----------                                                        

                           [Form of Right Certificate]


Certificate No. R-                                           ____________ Rights


NOT  EXERCISABLE  AFTER SEPTEMBER 23, 1998 OR EARLIER IF NOTICE OF REDEMPTION IS
GIVEN.  THE RIGHTS ARE SUBJECT TO REDEMPTION,  AT THE OPTION OF THE COMPANY,  AT
$0.02 PER RIGHT ON THE TERMS SET FORTH IN THE RIGHTS  AGREEMENT.  [UNDER CERTAIN
CIRCUMSTANCES, RIGHTS BENEFICIALLY OWNED BY AN ACQUIRING PERSON (AS SUCH TERM IS
DEFINED IN THE RIGHTS  AGREEMENT) AND ANY  SUBSEQUENT  HOLDER OF SUCH RIGHTS MAY
BECOME NULL AND VOID].  (THE RIGHTS  REPRESENTED BY THIS CERTIFICATE ARE OR WERE
BENEFICIALLY  OWNED BY A PERSON  WHO WAS OR  BECAME  AN  ACQUIRING  PERSON OR AN
ASSOCIATE OR AFFILIATE OF AN ACQUIRING  PERSON (AS SUCH TERMS ARE DEFINED IN THE
RIGHTS AGREEMENT).  THIS RIGHT CERTIFICATE AND THE RIGHTS REPRESENTED HEREBY MAY
BECOME VOID UNDER  CERTAIN  CIRCUMSTANCES  AS  SPECIFIED  IN SECTION 7(6) OF THE
RIGHTS AGREEMENT.]


                                Right Certificate

                               PERINI CORPORATION


This  certifies  that   ___________________,   or  registered  assigns,  is  the
registered owner of the number of Rights set forth above, each of which entitles
the owner  thereof,  subject  to the terms,  provisions  and  conditions  of the
Shareholder  Rights  Agreement  dated as of September 23, 1988, as amended as of
May  17,  1990  (the  "Rights   Agreement")   between  Perini   Corporation,   a
Massachusetts corporation (the "Company"), and The First National Bank of Boston
(the  "Rights  Agent"),  to  purchase  from the  Company  at any time  after the
Distribution Date (as such term is defined in the Rights Agreement) and prior to
the close of  business  on  September  23,  1998 at the office or offices of the
Rights Agent designated for such purpose, or its successors as Rights Agent, one
one-hundredth of a share of a fully paid,  non-assessable  share of the Series A
Junior  Participating  Cumulative Preferred Stock (the "Preferred Stock") of the
Company,  at a purchase price of $________ per one one-hundredth of a share (the
"Exercise  Price"),  upon  presentation and surrender of this Right  Certificate
with the Form of Election to Purchase and the related Certificate duly executed.
The  number of Rights  evidenced  by this Right  Certificate  (and the number of
shares which may be purchased  upon exercise  thereof) set forth above,  and the
Exercise  Price per share set forth above,  are the number and Exercise Price as
of September 23, 1988, based on the Preferred Stock as constituted at such date.

     Upon the occurrence of a Section  11(a)(ii)  Event (as such term is defined
in the Rights Agreement),  if the Rights evidenced by this Right Certificate are
beneficially  owned by (i) an  Acquiring  Person or an Affiliate or Associate of
any such Acquiring  Person (as such terms are defined in the Rights  Agreement),
(ii) a transferee of any such Acquiring Person, Associate or Affiliate, or (iii)
under certain circumstances specified in the Rights Agreement, a transferee of a
Person who, after such transfer,  became a Acquiring  Person, or an Affiliate or
Associate of an Acquiring Person,  such Rights shall become null and void and no
holder  hereof  shall have any right with  respect to such Rights from and after
the occurrence of such Section 11(a)(ii) Event.

     As provided in the Rights  Agreement,  the Exercise Price and the number of
shares of Preferred  Stock or other  securities  which may be purchased upon the
exercise  of the Rights  evidenced  by this  Right  Certificate  are  subject to
modification and adjustment upon the happening of certain events.

     This Right  Certificate  is subject  to all of the  terms,  provisions  and
conditions of the Rights Agreement,  which terms,  provisions and conditions are
hereby  incorporated  herein by  reference  and made a part  hereof and to which
Rights Agreement  reference is hereby made for a full description of the rights,
limitations  of rights,  obligations,  duties and  immunities  hereunder  of the
Rights  Agent,  the  Company and the  holders of the Right  Certificates,  which
limitations of rights include the temporary  suspension of the exercisability of
such Rights under the specific  circumstances set forth in the Rights Agreement.
Copies of the  Rights  Agreement  are on file at the  principal  offices  of the
Company and the Rights Agent and are also available upon written  request to the
Company or the Rights Agent.

     This Right  Certificate,  with or without  other Right  Certificates,  upon
surrender  at the  office or offices of the  Rights  Agent  designated  for such
purpose,  may be exchanged for another Right Certificate or Certificates of like
tenor  and date  evidencing  Rights  entitling  the  holder to  purchase  a like
aggregate  number of shares of  Preferred  Stock as the Rights  evidenced by the
Right Certificate or Certificates surrendered shall have entitled such holder to
purchase. If this Right Certificate shall be exercised in part, the holder shall
be entitled to receive  upon  surrender  hereof  another  Right  Certificate  or
Certificates for the number of whole Rights not exercised.

     Subject to the provisions of the Rights Agreement,  the Rights evidenced by
this Certificate may be redeemed by the Board of Directors of the Company at its
option at a redemption  price of $0.02 per Right (payable in cash,  Common Stock
or other consideration deemed appropriate by the Board of Directors).

     No fractional shares of stock will be issued upon the exercise of any Right
or Rights evidenced hereby (other than fractions which are integral multiples of
one  one-hundredth of a share of Preferred Stock,  which may, at the election of
the Company,  be evidenced by depositary  receipts),  but in lieu thereof a cash
payment will be made, as provided in the Rights Agreement.

     No holder of this Right  Certificate  shall be  entitled to vote or receive
dividends or be deemed for any purpose the holder of shares of Preferred  Stock,
Common  Stock or any other  securities  of the Company  which may at any time be
issuable on the  exercise  hereof,  nor shall  anything  contained in the Rights
Agreement or herein be construed to confer upon the holder hereof,  as such, any
of the  rights  of a  stockholder  of the  Company  or any right to vote for the
election  of  directors  or upon any matter  submitted  to  stockholders  at any
meeting thereof,  or to give or withhold consent to any corporate  action, or to
receive notice of meetings or other actions  affecting  stockholders  (except as
provided  in the Rights  Agreement),  or to receive  dividends  or  subscription
rights,  or  otherwise,  until  the  Right or  Rights  evidenced  by this  Right
Certificate shall have been exercised as provided in the Rights Agreement.

     This Right  Certificate  shall not be valid or  obligatory  for any purpose
until it shall have been countersigned by the Rights Agent.

     WITNESS the facsimile  signature of the proper  officers of the Company and
its corporate seal.

[Corporate Seal]                                 PERINI CORPORATION

Attested:                                        By___________________________
                                                    Name:
                                                    Title: [Chairman, President
By________________________                                  or Vice President]
[Clerk or Assistant Clerk]


Countersigned:                                   _____________________________
                                                    Name:
THE FIRST NATIONAL BANK OF                          Title: [Treasurer or
  BOSTON, as Rights Agent                                   Assistant Treasurer]


- --------------------------
Authorized Signature


                   [Form of Reverse Side of Right Certificate]

                               FORM OF ASSIGNMENT


FOR VALUE RECEIVED_____________________________________________
hereby sells, assigns and transfers unto
- ---------------------------------------------------------------
(Please print name and address of transferee)
- ---------------------------------------------------------------
this Right Certificate, together with all right, title and interest therein, and
does hereby  irrevocably  constitute and appoint  _______________  Attorney,  to
transfer the within Right Certificate on the books of the within-named  Company,
with full power of substitution.

Dated: _______________, 19__

                                                 ----------------------------
                                                 Signature


Signature Guaranteed:________________________


                                   CERTIFICATE
                                   -----------

         The  undersigned  hereby  certifies by checking the  appropriate  boxes
that:

         (1) the Rights  evidenced by this Right  Certificate ____ are _____ are
not being  transferred  by or on behalf of a Person  who is or was an  Acquiring
Person or an Affiliate or Associate of any such Acquiring  Person (as such terms
are defined in the Rights Agreement); and

         (2) after due inquiry and to the best knowledge of the undersigned, the
undersigned  ___ did ___ did not  directly  or  indirectly  acquire  the  Rights
evidenced  by this  Right  Certificate  from any Person who is, was or became an
Acquiring Person or an Affiliate or Associate of an Acquiring Person.

Dated: _____________, 19__                  _____________________________
                                            Signature



                                     NOTICE
                                     ------


         The  signature  to  the  foregoing   Assignment  and  Certificate  must
correspond  to the name as written  upon the face of this Right  Certificate  in
every particular, without alteration or enlargement or any change whatsoever.



                          FORM OF ELECTION TO PURCHASE
                          ----------------------------

                      (To be executed if holder desires to
                        exercise the Right Certificate.)

To PERINI CORPORATION:

     The undersigned hereby irrevocably elects to exercise  ____________  Rights
represented by this Right  Certificate to purchase the shares of Preferred Stock
issuable  upon the  exercise  of the  Rights (or such  other  securities  of the
Company or of any other  person  which may be issuable  upon the exercise of the
Rights) and requests that certificates for such shares be issued in the name of:

Please insert social security
or other identifying number: ___________________________________

- ----------------------------------------------------------------
                         (Please print name and address)

- ----------------------------------------------------------------


     If such  number of Rights  shall not be all the  Rights  evidenced  by this
Right Certificate,  a new Right Certificate for the balance of such Rights shall
be registered in the name of and delivered to:

Please insert social security
or other identifying number:____________________________________

- ----------------------------------------------------------------
                         (Please print name and address)
- ----------------------------------------------------------------

- ----------------------------------------------------------------

Dated: ______________, 19__
                                                 -----------------------------
                                                 Signature

Signature Guaranteed:_______________________



                                   CERTIFICATE
                                   -----------


     The undersigned hereby certifies by checking the appropriate boxes that:

     (1) the Rights  evidenced by this Right  Certificate  ____ are ____ are not
being exercised by or on behalf of a Person who is or was an Acquiring Person or
an  Affiliate  or  Associate  of any such  Acquiring  Person  (as such terms are
defined in the Rights Agreement); and

     (2) after due inquiry and to the best  knowledge  of the  undersigned,  the
undersigned  ____ did ____ did not  directly  or  indirectly  acquire the Rights
evidenced  by this  Right  Certificate  from any Person who is, was or became an
Acquiring Person or an Affiliate or Associate of an Acquiring Person.


Dated:_________________, 19__                    _____________________________
                                                 Signature



                                     NOTICE
                                     ------

     The signature to the foregoing  Election to Purchase and  Certificate  must
correspond  to the name as written  upon the face of this Right  Certificate  in
every particular, without alteration or enlargement or any change whatsoever.