EXHIBIT C                                                         
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                  SUMMARY OF RIGHTS TO PURCHASE PREFERRED STOCK


         On  September  23, 1988,  the Board of Directors of Perini  Corporation
(the "Company") declared a dividend distribution of one Preferred Stock Purchase
Right for each outstanding  share of Common Stock of the Company to stockholders
of record at the close of business on October 6, 1988.  Each Right  entitles the
registered  holder  to  purchase  from  the  Company  a unit  consisting  of one
one-hundredth of a share (a "Unit") of Series A Junior Participating  Cumulative
Preferred  Stock, par value $1.00 per share (the "Preferred  Stock"),  at a cash
Exercise Price of $100.00 per Unit,  subject to adjustment.  The description and
terms of the Rights are set forth in a Shareholder  Rights Agreement dated as of
September  23,  1988,  as amended as of May 17, 1990 between the Company and The
First National Bank of Boston, as Rights Agent.

         Initially,  the Rights will not be exercisable  and will be attached to
all outstanding  shares of Common Stock. No separate Right  Certificates will be
distributed  until the  Distribution  Date.  The Rights will  separate  from the
Common  Stock and the  Distribution  Date will occur upon the earliest of (i) 10
days  following a public  announcement  that a person or group of  affiliated or
associated  persons  (other than the Company and certain of its  affiliates  and
other exempted persons)(an "Acquiring Person") has acquired beneficial ownership
of 20% or more of the  outstanding  shares  of  Common  Stock  (the date of said
announcement  being  referred  to as the  "Stock  Acquisition  Date"),  (ii)  10
business days  following the  commencement  of a tender offer or exchange  offer
that would result in a person or group becoming an Acquiring Person or (iii) the
declaration by the Board of Directors that any person is an "Adverse Person."

         The Board of Directors  could declare a person to be an Adverse  Person
after  (1) a  determination  that  such  person,  alone  or  together  with  its
affiliates and associates, has become the beneficial owner of 10% or more of the
outstanding  shares of  Common  Stock  and (2) a  determination  by the Board of
Directors,   after  reasonable   inquiry  and   investigation,   including  such
consultation,   if  any,  with  such  persons  as  such  directors   shall  deem
appropriate,  that (a) such  beneficial  ownership by such person is intended to
cause, is reasonably likely to cause or will cause the Company to repurchase the
Common  Stock  beneficially  owned by such  person or to cause  pressure  on the
Company to take  action or enter into a  transaction  or series of  transactions
which  would  provide  such  person  with   short-term   financial   gain  under
circumstances  where the Board of Directors  determines  that the best long-term
interests of the Company and its stockholders,  but for the actions and possible
actions of such  person,  would not be served by taking  such action or entering
into  such  transaction  or  series  of  transactions  at that  time or (b) such
beneficial  ownership  is  causing or is  reasonably  likely to cause a material
adverse impact (including,  but not limited to, impairment of relationships with
customers or  impairment of the  Company's  ability to maintain its  competitive
position) on the business or prospects of the Company;  provided,  however, that
the Board of  Directors of the Company may not declare a person to be an Adverse
Person if, prior to the time that such person acquired 10% or more of the shares
of Common Stock then outstanding, such person provided to the Board of Directors
in writing a statement of such  person's  purpose and  intentions  in connection
with  the  proposed  acquisition  of  Common  Stock,  together  with  any  other
information  reasonably requested of such person by the Board of Directors,  and
the Board of Directors,  based on such statement and such reasonable inquiry and
investigation,  including  such  consultation,  if any, with such persons as the
directors shall deem appropriate,  determines to notify and notifies such person
in writing that it will not declare such person to be Adverse  Person;  provided
further,  that the Board of Directors  may  expressly  condition in any manner a
determination  not to declare a person an Adverse  Person on such  conditions as
the Board of Directors may select,  including  without  limitation such person's
not acquiring more than a specified  amount of stock and/or on such person's not
taking actions  inconsistent with the purposes and intentions  disclosed by such
person in the statement provided to the Board of Directors.  No delay or failure
by the Board of Directors  to declare a person to be an Adverse  Person shall in
any  way  waive  or  otherwise  affect  the  power  of the  Board  of  Directors
subsequently to declare a person to be an Adverse Person.  In the event that the
Board of Directors  should at any time determine,  upon  reasonable  inquiry and
investigation,  including  consultation with such persons as the directors shall
deem  appropriate,  that such person has not met or complied  with any condition
specified  by the Board of  Directors,  the Board of  Directors  may at any time
thereafter declare the person to be an Adverse Person.

         Until the Distribution Date (or earlier redemption or expiration of the
Rights),  (a) the Rights will be evidenced by the Common Stock  certificates and
will be transferred with and only with such Common Stock  certificates,  (b) new
Common Stock  certificates  issued after October 6, 1988 will contain a notation
incorporating  the  Shareholder  Rights  Agreement  by  reference,  and  (c) the
surrender for transfer of any certificates for Common Stock will also constitute
the transfer of the Rights  associated with the Common Stock represented by such
certificate.

         The Rights are not  exercisable  until the  Distribution  Date and will
expire at the  close of  business  on  September  23,  1998,  unless  previously
redeemed by the Company as described below.

         As soon as practicable after the Distribution  Date, Right Certificates
will be mailed to holders of record of Common  Stock as of the close of business
on the Distribution Date and, thereafter,  the separate Right Certificates alone
will  represent  the  Rights.  Except as  otherwise  determined  by the Board of
Directors,  only shares of Common Stock issued  prior to the  Distribution  Date
will be issued with Rights.

         In the  event  that a Stock  Acquisition  Date  occurs  or the Board of
Directors  determines that a person is an Adverse Person,  proper provision will
be made so that each holder of a Right will thereafter have the right to receive
upon  exercise that number of Units of Preferred  Stock of the Company  having a
market  value of two times the  exercise  price of the Right  (such  right being
referred  to as the  "Subscription  Right").  In the  event  that,  at any  time
following the Stock Acquisition Date, (i) the Company is acquired in a merger or
other  business  combination  transaction  or (ii) 50% or more of the  Company's
assets or earning power is sold,  each holder of a Right shall  thereafter  have
the right to receive,  upon  exercise,  common  stock of the  acquiring  company
having a market value equal to two times the  exercise  price of the Right (such
right  being  referred  to as the  "Merger  Right").  The holder of a Right will
continue to have the Merger Right  whether or not such holder has  exercised the
Subscription  Right.  Rights that are or were beneficially owned by an Acquiring
Person or an Adverse  Person may (under certain  circumstances  specified in the
Shareholder Rights Agreement) become null and void.

         At any time  after a Stock  Acquisition  Date  occurs  or the  Board of
Directors  determines that a person is an Adverse Person, the Board of Directors
may,  at its  option,  exchange  all or any  part of the  then  outstanding  and
exercisable  Rights for shares of Common Stock or Units of Preferred Stock at an
exchange  ratio of one share of Common Stock or one Unit of Preferred  Stock per
Right.

         The Exercise Price payable,  and the number of Units of Preferred Stock
or other  securities  or  property  issuable,  upon  exercise  of the Rights are
subject to adjustment from time to time to prevent  dilution (i) in the event of
a stock dividend on, or a subdivision,  combination or reclassification  of, the
Preferred  Stock,  (ii) if holders of the  Preferred  Stock are granted  certain
rights or warrants to subscribe for Preferred Stock or convertible securities at
less than the current  market price of the  Preferred  Stock,  or (iii) upon the
distribution  to holders of the Preferred  Stock of evidences of indebtedness or
assets (excluding regular quarterly cash dividends) or of subscription rights or
warrants (other than those referred to above).

         With certain  exceptions,  no adjustment in the Exercise  Price will be
required  until  cumulative  adjustments  amount to at least 1% of the  Exercise
Price.  The Company is not obligated to issue  fractional  Units. If the Company
elects not to issue fractional Units, in lieu thereof an adjustment in cash will
be made  based  on the fair  market  value  of the  Preferred  Stock on the last
trading date prior to the date of exercise.

         Any of  the  provisions  of the  Shareholder  Rights  Agreement  may be
amended  by the  Board of  Directors  of the  Company  at any time  prior to the
Distribution  Date. From and after the Distribution Date, the Board of Directors
of the  Company  may,  subject to certain  limitations  specified  in the Rights
Agreement,  amend  the  Rights  Agreement  to  cure  any  ambiguity,  defect  or
inconsistency,  to  shorten  or  lengthen  any  time  period  under  the  Rights
Agreement,  or to make other changes that do not adversely  affect the interests
of the Rights  holders  (excluding the interests of Acquiring  Persons,  Adverse
Persons or their Affiliates or Associates).

         The Rights may be  redeemed  in whole,  but not in part,  at a price of
$0.02 per Right  (payable in cash,  Common Stock or other  consideration  deemed
appropriate  by the Board of  Directors)  by the Board of  Directors at any time
prior to the date on which a person is  declared  to be an Adverse  Person,  the
tenth day after the Stock  Acquisition Date or the occurrence of an event giving
rise to the Merger Right.  Immediately upon the action of the Board of Directors
ordering  redemption of the Rights, the Rights will terminate and thereafter the
only right of the holders of Rights will be to receive the redemption price.

         Until a Right  is  exercised,  the  holder  will  have no  rights  as a
stockholder of the Company (beyond those as an existing stockholder),  including
the right to vote or to receive dividends.  While the distribution of the Rights
will  not be  taxable  to  stockholders  or to the  Company,  stockholders  may,
depending upon the circumstances, recognize taxable income in the event that the
Rights become  exercisable for Preferred Stock (or other  consideration)  of the
Company or for common stock of an acquiring company as set forth above.

         A copy of the  Shareholder  Rights  Agreement dated as of September 23,
1988,  as  amended  and  restated  as of May 17,  1990,  has been filed with the
Securities and Exchange Commission as an Exhibit to a Current Report on Form 8-K
dated May 17, 1990. A copy of the Shareholder Rights Agreement is available free
of charge from the  Company.  This  summary  description  of the Rights does not
purport to be complete  and is  qualified  in its  entirety by  reference to the
Shareholder Rights Agreement.