EXECUTION COPY


                                                                       Exhibit A


                             STOCK OPTION AGREEMENT


         STOCK  OPTION  AGREEMENT,  dated as of June 27,  2000,  between  Queens
County Bancorp,  Inc., a Delaware  corporation  ("Grantee"),  and Haven Bancorp,
Inc., a Delaware corporation ("Issuer").

                              W I T N E S S E T H:

         WHEREAS,  Grantee and Issuer are entering into an Agreement and Plan of
Merger (the "Merger Agreement");

         WHEREAS,  as a condition and an  inducement to Grantee's  entering into
the  Merger  Agreement,  Issuer  has  agreed to grant  Grantee  the  Option  (as
hereinafter  defined) on the terms and conditions  set forth in this  Agreement;
and

         WHEREAS, the Board of Directors of Issuer has approved the grant of the
Option and the Merger Agreement prior to the date hereof;

         NOW,  THEREFORE,  in  consideration  of the  foregoing  and the  mutual
covenants  and  agreements  set forth  herein and in the Merger  Agreement,  the
parties hereto agree as follows:

         1. (a)  Issuer  hereby  grants to Grantee an  irrevocable  option  (the
"Option")  to  purchase,  subject to the terms  hereof,  up to an  aggregate  of
1,800,000  fully paid and  nonassessable  shares of the common stock,  par value
$0.01 per share,  of Issuer  ("Common  Stock") at a price per share equal to the
last  reported  sale price per share of Common Stock as reported on the National
Association of Securities Dealers Composite  Transactions Tape on June 28, 2000;
provided, however, that in the event Issuer issues or agrees to issue any shares
of Common  Stock  (other than shares of Common  Stock  issued  pursuant to stock
options granted  pursuant to any employee benefit plan prior to the date hereof)
at a price  less than such  average  price per share (as  adjusted  pursuant  to
subsection  (b) of Section  5), the price  shall be equal to such  lesser  price
(such price, as adjusted if applicable, the "Option Price"); provided,  further,
that in no event shall the number of shares for which this Option is exercisable
exceed 19.9% of the issued and outstanding shares of Common Stock. The number of
shares of Common Stock that may be received  upon the exercise of the Option and
the Option Price are subject to adjustment as herein set forth.

         (b) In the event that any additional  shares of Common Stock are issued
or otherwise  become  outstanding  after the date of this Agreement  (other than
pursuant to this  Agreement  and other than  pursuant to an event  described  in
Section 5(a) hereof), the number of shares of Common Stock subject to the Option
shall be increased so that,  after such issuance,  such number together with any
shares of Common Stock previously  issued pursuant  hereto,  equals 19.9%

<PAGE>

of the number of shares of Common  Stock then  issued  and  outstanding  without
giving effect to any shares  subject or issued  pursuant to the Option.  Nothing
contained in this Section l(b) or elsewhere in this Agreement shall be deemed to
authorize  Issuer  to issue  shares in breach  of any  provision  of the  Merger
Agreement.

         2. (a) The Holder (as hereinafter  defined) may exercise the Option, in
whole or part, if, but only if, both an Initial Triggering Event (as hereinafter
defined) and a Subsequent  Triggering Event (as hereinafter  defined) shall have
occurred  prior  to  the  occurrence  of  an  Exercise   Termination  Event  (as
hereinafter  defined),  provided  that the Holder  shall  have sent the  written
notice of such exercise (as provided in subsection (e) of this Section 2) within
six (6) months following such Subsequent  Triggering Event (or such later period
as  provided  in  Section  10).  Each  of the  following  shall  be an  Exercise
Termination Event: (i) the Effective Time of the Merger; (ii) termination of the
Merger  Agreement in accordance with the provisions  thereof if such termination
occurs  prior  to  the  occurrence  of an  Initial  Triggering  Event  except  a
termination by Grantee pursuant to Section 6.1(b)(ii) of the Merger Agreement (a
"Listed  Termination");  or (iii) the  passage  of twelve  (12)  months (or such
longer  period as  provided  in  Section  10) after  termination  of the  Merger
Agreement if such  termination  follows the occurrence of an Initial  Triggering
Event or is a Listed  Termination.  The term  "Holder"  shall mean the holder or
holders of the Option.

         (b) The term "Initial Triggering Event" shall mean any of the following
events or transactions occurring on or after the date hereof:

          (i)  Issuer or any  subsidiary  or group of  subsidiaries  that is, or
     would on an  aggregate  basis  constitute,  a  Significant  Subsidiary  (as
     defined in Rule 1-02 of Regulation  S-X  promulgated  by the Securities and
     Exchange  Commission  (the  "SEC"))  (each  such  subsidiary  or  group  of
     subsidiaries,  an "Issuer  Subsidiary"),  without having received Grantee's
     prior written consent, shall have entered into an agreement to engage in an
     Acquisition  Transaction (as hereinafter defined) with any person (the term
     "person" for purposes of this Agreement having the meaning assigned thereto
     in Sections 3(a)(9) and 13(d)(3) of the Securities Exchange Act of 1934, as
     amended (the "1934 Act"), and the rules and regulations  thereunder)  other
     than Grantee or any of its  Subsidiaries  (each a "Grantee  Subsidiary") or
     the  Board  of  Directors  of  Issuer  (the  "Issuer   Board")  shall  have
     recommended   that  the  shareholders  of  Issuer  approve  or  accept  any
     Acquisition Transaction other than as contemplated by the Merger Agreement.
     For purposes of this Agreement,  (a) "Acquisition  Transaction"  shall mean
     (x) a merger or consolidation, or any similar transaction, involving Issuer
     or any Issuer  Subsidiary  (other than mergers,  consolidations  or similar
     transactions  involving  solely  Issuer  and/or  one or  more  wholly-owned
     Subsidiaries of the Issuer,  provided,  any such transaction is not entered
     into in  violation of the terms of the Merger  Agreement),  (y) a purchase,
     lease or other  acquisition of all or any substantial part of the assets or
     deposits of Issuer or any Issuer  Subsidiary  (except  for any  supermarket
     branches  and  related  deposits  of the  Issuer  located  in New Jersey or
     Connecticut),  or (z) a purchase or other acquisition  (including by way of
     merger,   consolidation,   share   exchange  or  otherwise)  of  securities
     representing 10% or more of the voting power of Issuer or any Issuer

                                       -2-
<PAGE>

     Subsidiary  and (b)  "Subsidiary"  shall have the meaning set forth in Rule
     12b-2 under the 1934 Act;

          (ii) Any person other than the Grantee or any Grantee Subsidiary shall
     have  acquired  beneficial  ownership  or the right to  acquire  beneficial
     ownership  of 10% or more of the  outstanding  shares of Common  Stock (the
     term  "beneficial  ownership"  for  purposes of this  Agreement  having the
     meaning  assigned  thereto in Section  13(d) of the 1934 Act, and the rules
     and regulations thereunder);

          (iii)  The  shareholders  of Issuer  shall  have  voted and  failed to
     approve  the Merger  Agreement  and the Merger at a meeting  which has been
     held for that purpose or any adjournment or postponement  thereof,  or such
     meeting  shall not have been held in violation  of the Merger  Agreement or
     shall have been canceled prior to  termination of the Merger  Agreement if,
     prior to such meeting (or if such meeting shall not have been held or shall
     have been canceled, prior to such termination), it shall have been publicly
     announced  that any person (other than Grantee or any of its  Subsidiaries)
     shall have made, or disclosed an intention to make, a bona fide proposal to
     engage in an Acquisition Transaction;

          (iv) The Issuer  Board shall have  withdrawn  or modified (or publicly
     announced its intention to withdraw or modify) in any manner adverse in any
     respect to  Grantee  its  recommendation  that the  shareholders  of Issuer
     approve the  transactions  contemplated  by the Merger  Agreement  after it
     shall have been publicly  announced  that any person (other than Grantee or
     any of its  Subsidiaries)  shall have made,  or  disclosed  an intention to
     make,  a bona fide  proposal to engage in an  Acquisition  Transaction,  or
     Issuer  or  any  Issuer  Subsidiary  shall  have  authorized,  recommended,
     proposed (or publicly  announced its  intention to authorize,  recommend or
     propose) an  agreement  to engage in an  Acquisition  Transaction  with any
     person other than Grantee or a Grantee Subsidiary;

          (v) Any person other than Grantee or any Grantee Subsidiary shall have
     made a bona fide  proposal  to Issuer or its  shareholders  to engage in an
     Acquisition   Transaction  and  such  proposal  shall  have  been  publicly
     announced; or

          (vi) Any person  other than  Grantee or any Grantee  Subsidiary  shall
     have filed with the SEC a registration  statement or tender offer materials
     with respect to a potential  exchange or tender offer that would constitute
     an Acquisition Transaction (or filed a preliminary proxy statement with the
     SEC with  respect to a potential  vote by its  shareholders  to approve the
     issuance of shares to be offered in such an exchange offer).

         (c) The  term  "Subsequent  Triggering  Event"  shall  mean  any of the
following events or transactions occurring after the date hereof:

          (i) The  acquisition  by any person (other than Grantee or any Grantee
     Subsidiary) of beneficial  ownership of 25% or more of the then outstanding
     Common Stock; or

                                      -3-
<PAGE>

          (ii) The  occurrence  of the Initial  Triggering  Event  described  in
     clause (i) of subsection  (b) of this Section 2, except that the percentage
     referred to in clause (z) of the second sentence thereof shall be 25%.

         (d) Issuer shall notify  Grantee  promptly in writing of the occurrence
of any Initial  Triggering Event or Subsequent  Triggering  Event  (together,  a
"Triggering  Event"),  it being  understood  that the  giving of such  notice by
Issuer  shall not be a  condition  to the right of the  Holder to  exercise  the
Option.

         (e) In the event the Holder is entitled  to and wishes to exercise  the
Option (or any portion  thereof),  it shall send to Issuer a written notice (the
date of which being herein referred to as the "Notice Date")  specifying (i) the
total  number of shares it will  purchase  pursuant to such  exercise and (ii) a
place and date not earlier than three  business  days nor later than 60 business
days from the Notice Date for the closing of such purchase (the "Closing Date");
provided,  that if prior  notification  to or  approval  of the Office of Thrift
Supervision  (the "OTS") Board of Governors of the Federal  Reserve  System (the
"Federal Reserve Board") or any other regulatory or antitrust agency is required
in connection  with such  purchase,  the Holder shall promptly file the required
notice or application for approval, shall promptly notify Issuer of such filing,
and shall  expeditiously  process the same and the period of time that otherwise
would run pursuant to this sentence shall run instead from the date on which any
required  notification periods have expired or been terminated or such approvals
have been  obtained  and any  requisite  waiting  period or  periods  shall have
passed.  Any  exercise of the Option shall be deemed to occur on the Notice Date
relating thereto.

         (f) At the closing referred to in subsection (e) of this Section 2, the
Holder shall (i) pay to Issuer the  aggregate  purchase  price for the shares of
Common Stock  purchased  pursuant to the  exercise of the Option in  immediately
available funds by wire transfer to a bank account designated by Issuer and (ii)
present  and  surrender  this  Agreement  to Issuer at its  principal  executive
offices,  provided that the failure or refusal of the Issuer to designate such a
bank account or accept surrender of this Agreement shall not preclude the Holder
from exercising the Option.

         (g) At such closing,  simultaneously  with the delivery of  immediately
available  funds as provided in  subsection  (f) of this Section 2, Issuer shall
deliver to the Holder a certificate or certificates  representing  the number of
shares of Common  Stock  purchased  by the Holder and,  if the Option  should be
exercised in part only, a new Option evidencing the rights of the Holder thereof
to purchase the balance of the shares purchasable hereunder.

         (h)  Certificates  for Common Stock  delivered  at a closing  hereunder
shall be endorsed with a  restrictive  legend that shall read  substantially  as
follows:

          "The transfer of the shares represented by this certificate is subject
     to  certain  provisions  of an  agreement,  dated as of  _________,  2000,
     between the registered holder hereof and Issuer and to resale  restrictions
     arising  under  the  Securities  Act of 1933,  as  amended.  A copy

                                      -4-
<PAGE>


     of such agreement is on file at the principal  office of Issuer and will be
     provided to the holder  hereof  without  charge upon receipt by Issuer of a
     written request therefor."

It is understood and agreed that:  (i) the reference to the resale  restrictions
of the  Securities  Act of 1933, as amended (the "1933 Act") in the above legend
shall be removed by delivery of substitute certificate(s) without such reference
if the Holder  shall have  delivered to Issuer a copy of a letter from the staff
of the  SEC,  or an  opinion  of  counsel,  in  form  and  substance  reasonably
satisfactory  to Issuer,  to the effect  that such  legend is not  required  for
purposes of the 1933 Act; (ii) the reference to the provisions of this Agreement
in the above  legend shall be removed by delivery of  substitute  certificate(s)
without such reference if the shares have been sold or transferred in compliance
with the  provisions  of this  Agreement  and  under  circumstances  that do not
require the retention of such reference in the opinion of counsel to the Holder;
and (iii) the legend shall be removed in its entirety if the  conditions  in the
preceding  clauses  (i)  and  (ii)  are  both  satisfied.   In  addition,   such
certificates shall bear any other legend as may be required by law.

         (i) Upon the  giving by the Holder to Issuer of the  written  notice of
exercise of the Option  provided for under  subsection (e) of this Section 2 and
the tender of the applicable purchase price in immediately  available funds, the
Holder  shall be deemed to be the holder of record of the shares of Common Stock
issuable upon such  exercise,  notwithstanding  that the stock transfer books of
Issuer  shall then be closed or that  certificates  representing  such shares of
Common Stock shall not then be actually  delivered  to the Holder.  Issuer shall
pay all expenses,  and any and all United States federal,  state and local taxes
and other charges that may be payable in connection with the preparation,  issue
and  delivery  of stock  certificates  under  this  Section 2 in the name of the
Holder or its assignee, transferee or designee.

         3. Issuer agrees:  (i) that it shall at all times  maintain,  free from
preemptive  rights,  sufficient  authorized  but unissued or treasury  shares of
Common   Stock  so  that  the  Option  may  be  exercised   without   additional
authorization  of  Common  Stock  after  giving  effect  to all  other  options,
warrants, convertible securities and other rights to purchase Common Stock; (ii)
that it will not, by charter amendment or through reorganization, consolidation,
merger,  dissolution or sale of assets,  or by any other voluntary act, avoid or
seek  to  avoid  the   observance  or  performance  of  any  of  the  covenants,
stipulations  or  conditions  to be observed or  performed  hereunder by Issuer;
(iii)  promptly  to take  all  action  as may  from  time  to  time be  required
(including (x) complying with all applicable premerger  notification,  reporting
and  waiting  period  requirements  specified  in  15  U.S.C.  Section  18a  and
regulations  promulgated thereunder and (y) in the event, under the Bank Holding
Company Act of 1956, as amended (the "BHCA"),  Home Owners' Loan Act, as amended
("HOLA") or the Change in Bank Control Act of 1978, as amended,  or any state or
other federal  banking law,  prior approval of or notice to the OTS, the Federal
Reserve Board or to any state or other federal regulatory authority is necessary
before  the  Option  may be  exercised,  cooperating  fully  with the  Holder in
preparing such applications or notices and providing such information to the OTS
or the Federal Reserve Board or such state or other federal regulatory authority
as they may  require) in order to permit the Holder to  exercise  the Option and
Issuer duly and effectively to


                                      -5-
<PAGE>


issue  shares of Common Stock  pursuant  hereto;  and (iv)  promptly to take all
action provided herein to protect the rights of the Holder against dilution.

         4. This  Agreement  and the Option  granted  hereby  are  exchangeable,
without expense, at the option of the Holder, upon presentation and surrender of
this Agreement at the principal office of Issuer, for other Agreements providing
for Options of different denominations entitling the holder thereof to purchase,
on the same terms and subject to the same conditions as are set forth herein, in
the aggregate the same number of shares of Common Stock  purchasable  hereunder.
The terms  "Agreement"  and "Option" as used herein  include any  Agreements and
related  Options for which this Agreement (and the Option granted hereby) may be
exchanged.  Upon receipt by Issuer of evidence reasonably  satisfactory to it of
the loss, theft,  destruction or mutilation of this Agreement,  and (in the case
of loss, theft or destruction) of reasonably satisfactory  indemnification,  and
upon surrender and  cancellation  of this Agreement,  if mutilated,  Issuer will
execute  and  deliver a new  Agreement  of like  tenor  and  date.  Any such new
Agreement  executed and delivered  shall  constitute  an additional  contractual
obligation on the part of Issuer,  whether or not the Agreement so lost, stolen,
destroyed or mutilated shall at any time be enforceable by anyone.

         5. In  addition  to the  adjustment  in the  number of shares of Common
Stock that are purchasable  upon exercise of the Option pursuant to Section 1 of
this  Agreement,  the  number of shares of  Common  Stock  purchasable  upon the
exercise of the Option and the Option Price shall be subject to adjustment  from
time to time as provided in this Section 5.

         (a) In the event of any change in, or  distributions in respect of, the
Common   Stock   by   reason   of   stock   dividends,    split-ups,    mergers,
recapitalizations,  combinations, subdivisions, conversions, exchanges of shares
or the like,  the type and  number of shares of Common  Stock  purchasable  upon
exercise hereof shall be  appropriately  adjusted and proper  provision shall be
made so that, in the event that any additional  shares of Common Stock are to be
issued or otherwise  become  outstanding  as a result of any such change  (other
than  pursuant  to an exercise  of the  Option),  the number of shares of Common
Stock that remain  subject to the Option shall be increased so that,  after such
issuance and together with shares of Common Stock previously  issued pursuant to
the  exercise  of the Option  (as  adjusted  on account of any of the  foregoing
changes in the Common Stock),  it equals 19.9% of the number of shares of Common
Stock then issued and outstanding.

         (b)  Whenever  the number of shares of Common  Stock  purchasable  upon
exercise  hereof is adjusted as  provided  in this  Section 5, the Option  Price
shall be adjusted by multiplying  the Option Price by a fraction,  the numerator
of which  shall be equal to the  number of shares  of Common  Stock  purchasable
prior to the  adjustment  and the  denominator  of  which  shall be equal to the
number of shares of Common Stock purchasable after the adjustment.

         6. Upon the  occurrence  of a Subsequent  Triggering  Event that occurs
prior to an Exercise  Termination Event, Issuer shall, at the request of Grantee
delivered within twelve (12) months (or such later period as provided in Section
10) of such Subsequent  Triggering Event


                                      -6-
<PAGE>

(whether on its own behalf or on behalf of any subsequent  holder of this Option
(or part thereof) or any of the shares of Common Stock issued pursuant  hereto),
promptly prepare, file and keep current a registration  statement under the 1933
Act  covering any shares  issued and issuable  pursuant to this Option and shall
use its commmercially reasonable efforts to cause such registration statement to
become  effective  and  remain  current  in  order to  permit  the sale or other
disposition of any shares of Common Stock issued upon total or partial  exercise
of this Option  ("Option  Shares") in  accordance  with any plan of  disposition
requested by Grantee.  Issuer will use its  commercially  reasonable  efforts to
cause such  registration  statement  promptly  to become  effective  and then to
remain  effective  for such  period  not in excess of 180 days from the day such
registration  statement  first becomes  effective or such shorter time as may be
reasonably  necessary to effect such sales or other dispositions.  Grantee shall
have the right to demand two such registrations. The Issuer shall bear the costs
of such registrations (including,  but not limited to, Issuer's attorneys' fees,
printing  costs  and  filing  fees,   except  for   underwriting   discounts  or
commissions,  brokers' fees and the fees and  disbursements of Grantee's counsel
related thereto). The foregoing notwithstanding,  if, at the time of any request
by Grantee for  registration  of Option Shares as provided  above,  Issuer is in
registration with respect to an underwritten public offering by Issuer of shares
of Common Stock,  and if in the good faith judgment of the managing  underwriter
or managing underwriters,  or, if none, the sole underwriter or underwriters, of
such offering the offer and sale of the Option Shares would  interfere  with the
successful marketing of the shares of Common Stock offered by Issuer, the number
of  Option  Shares  otherwise  to  be  covered  in  the  registration  statement
contemplated  hereby  may be  reduced;  provided,  however,  that after any such
required  reduction  the number of Option Shares to be included in such offering
for the account of the Holder shall  constitute at least 25% of the total number
of shares to be sold by the  Holder and Issuer in the  aggregate;  and  provided
further,  however,  that if such  reduction  occurs,  then  Issuer  shall file a
registration  statement for the balance as promptly as practicable thereafter as
to which no reduction pursuant to this Section 6 shall be permitted or occur and
the Holder shall  thereafter be entitled to one additional  registration and the
twelve (12) month period referred to in the first sentence of this section shall
be increased to  twenty-four  (24)  months.  Each such Holder shall  provide all
information  reasonably  requested by Issuer for  inclusion in any  registration
statement to be filed  hereunder.  If requested by any such Holder in connection
with  such  registration,  Issuer  shall  become  a  party  to any  underwriting
agreement  relating  to the  sale of such  shares,  but  only to the  extent  of
obligating  itself in respect of  representations,  warranties,  indemnities and
other  agreements  customarily  included  in such  underwriting  agreements  for
Issuer. Upon receiving any request under this Section 6 from any Holder,  Issuer
agrees to send a copy thereof to any other person known to Issuer to be entitled
to  registration  rights under this Section 6, in each case by promptly  mailing
the same,  postage prepaid,  to the address of record of the persons entitled to
receive such copies.  Notwithstanding anything to the contrary contained herein,
in no event shall the number of registrations that Issuer is obligated to effect
be increased by reason of the fact that there shall be more than one Holder as a
result of any assignment or division of this Agreement.

         7. (a) At any time  after  the  occurrence  of a  Repurchase  Event (as
defined  below)  and  prior  to the  date  that  is six (6)  months  immediately
thereafter  (i) at the  request of the  Holder,  delivered  prior to an Exercise
Termination  Event (or such later period as provided in Section 10),  Issuer (or
any successor thereto) shall repurchase the Option from the

                                      -7-
<PAGE>

Holder at a price (the "Option  Repurchase  Price") equal to the amount by which
(A) the  market/offer  price (as defined  below)  exceeds (B) the Option  Price,
multiplied  by the number of shares for which this Option may then be  exercised
and (ii) at the  request  of the owner of Option  Shares  from time to time (the
"Owner"), delivered prior to an Exercise Termination Event (or such later period
as provided in Section 10), Issuer (or any successor  thereto) shall  repurchase
such number of the Option Shares from the Owner as the Owner shall  designate at
a price (the "Option Share Repurchase  Price") equal to the  market/offer  price
multiplied by the number of Option Shares so designated.  The term "market/offer
price"  shall  mean the  highest  of (i) the price per share of Common  Stock at
which a tender or  exchange  offer  therefor  has been made,  (ii) the price per
share of Common  Stock to be paid by any third party  pursuant  to an  agreement
with Issuer,  (iii) the highest  closing price for shares of Common Stock within
the one-month period  immediately  preceding the date the Holder gives notice of
the required repurchase of this Option or the Owner gives notice of the required
repurchase of Option Shares,  as the case may be, or (iv) in the event of a sale
of all or any substantial  part of Issuer's  assets or deposits,  the sum of the
net price paid in such sale for such assets or deposits  and the current  market
value of the  remaining  net  assets  of Issuer as  determined  by a  nationally
recognized  investment  banking firm selected by the Holder or the Owner, as the
case may be,  and  reasonably  acceptable  to  Issuer,  divided by the number of
shares  of Common  Stock of  Issuer  outstanding  at the time of such  sale.  In
determining the market/offer  price, the value of consideration  other than cash
shall be determined by a nationally  recognized investment banking firm selected
by the Holder or Owner, as the case may be, and reasonably acceptable to Issuer.

         (b) The  Holder and the Owner,  as the case may be,  may  exercise  its
right to require Issuer to repurchase the Option and any Option Shares  pursuant
to this Section 7 by surrendering  for such purpose to Issuer,  at its principal
office,  a copy  of  this  Agreement  or  certificates  for  Option  Shares,  as
applicable,  accompanied by a written notice or notices  stating that the Holder
or the Owner,  as the case may be, elects to require  Issuer to repurchase  this
Option  and/or the  Option  Shares in  accordance  with the  provisions  of this
Section 7. As promptly as  practicable,  and in any event  within five  business
days after the surrender of the Option and/or  certificates  representing Option
Shares and the receipt of such notice or notices relating thereto,  Issuer shall
deliver or cause to be  delivered  to the Holder  the  Option  Repurchase  Price
and/or to the Owner the Option Share  Repurchase  Price  therefor or the portion
thereof that Issuer is not then prohibited  under  applicable law and regulation
from so delivering.

         (c) To the extent that Issuer is  prohibited  under  applicable  law or
regulation,  or as a consequence of administrative policy, from repurchasing the
Option and/or the Option Shares in full,  Issuer shall immediately so notify the
Holder and/or the Owner and  thereafter  deliver or cause to be delivered,  from
time to time, to the Holder and/or the Owner, as appropriate, the portion of the
Option  Repurchase  Price and the Option Share Repurchase  Price,  respectively,
that it is no longer prohibited from delivering, within five business days after
the date on which Issuer is no longer so prohibited;  provided, however, that if
Issuer  at any  time  after  delivery  of a notice  of  repurchase  pursuant  to
paragraph  (b)  of  this  Section  7  is  prohibited  under  applicable  law  or
regulation, or as a consequence of administrative policy, from delivering to the
Holder and/or the Owner, as

                                      -8-
<PAGE>

appropriate,  the Option Repurchase Price and the Option Share Repurchase Price,
respectively,  in full (and Issuer hereby  undertakes to use its best efforts to
obtain (and to take all action necessary to obtain) all required  regulatory and
legal  approvals and to file any required  notices as promptly as practicable in
order to accomplish such repurchase),  the Holder or Owner may revoke its notice
of repurchase of the Option and/or the Option Shares  whether in whole or to the
extent of the prohibition,  whereupon, in the latter case, Issuer shall promptly
(i) deliver to the Holder and/or the Owner, as appropriate,  that portion of the
Option  Repurchase Price and/or the Option Share Repurchase Price that Issuer is
not prohibited from delivering; and (ii) deliver, as appropriate,  either (A) to
the Holder, a new Agreement  evidencing the right of the Holder to purchase that
number of shares of Common Stock obtained by multiplying the number of shares of
Common Stock for which the surrendered  Agreement was exercisable at the time of
delivery of the notice of  repurchase  by a fraction,  the numerator of which is
the Option  Repurchase Price less the portion thereof  theretofore  delivered to
the Holder and the denominator of which is the Option Repurchase  Price,  and/or
(B) to the Owner,  a certificate  for the Option Shares it is then so prohibited
from repurchasing. If an Exercise Termination Event shall have occurred prior to
the date of the  notice  by  Issuer  described  in the  first  sentence  of this
subsection (c), or shall be scheduled to occur at any time before the expiration
of a period  ending on the  thirtieth  day after  such date,  the  Holder  shall
nonetheless  have the right to exercise the Option until the  expiration of such
30-day period.

         (d) For  purposes  of this  Section 7, a  "Repurchase  Event"  shall be
deemed to have  occurred upon the  occurrence of any of the following  events or
transactions after the date hereof:

          (i) the  acquisition  by any person (other than Grantee or any Grantee
     Subsidiary) of beneficial  ownership of 50% or more of the then outstanding
     Common Stock; or

          (ii) the  consummation  of any  Acquisition  Transaction  described in
     Section  2(b)(i) hereof,  except that the percentage  referred to in clause
     (z) shall be 50%.

         8. (a) In the event  ("Substitute  Option Repurchase Event") that prior
to an Exercise  Termination  Event,  Issuer shall enter into an agreement (i) to
consolidate  with or merge  into any  person,  other  than  Grantee or a Grantee
Subsidiary,  or engage in a plan of exchange with any person, other than Grantee
or a Grantee  Subsidiary  and Issuer  shall not be the  continuing  or surviving
corporation  of such  consolidation  or merger or the  acquirer  in such plan of
exchange, (ii) to permit any person, other than Grantee or a Grantee Subsidiary,
to merge into Issuer or be  acquired by Issuer in a plan of exchange  and Issuer
shall  be  the  continuing  or  surviving  or  acquiring  corporation,  but,  in
connection with such merger or plan of exchange,  the then outstanding shares of
Common Stock shall be changed into or exchanged for stock or other securities of
any other person or cash or any other property or the then outstanding shares of
Common Stock shall after such merger or plan of exchange represent less than 50%
of the  outstanding  shares and share  equivalents  of the  merged or  acquiring
company, or (iii) to sell or otherwise transfer all or a substantial part of its
or any Issuer Subsidiary's assets or deposits to any person,  other than Grantee
or a Grantee  Subsidiary,  then, and in each such case, the agreement  governing
such transaction shall make proper provision so that the Option shall, upon the

                                      -9-

<PAGE>

consummation of any such transaction and upon the terms and conditions set forth
herein,  be  converted  into,  or  exchanged  for,  an option  (the  "Substitute
Option"), at the election of the Holder, of either (x) the Acquiring Corporation
(as  hereinafter  defined)  or  (y)  any  person  that  controls  the  Acquiring
Corporation.

         (b) The following terms have the meanings indicated:

          (i) "Acquiring Corporation" shall mean (i) the continuing or surviving
     person of a  consolidation  or merger with  Issuer (if other than  Issuer),
     (ii)  the  acquiring  person  in a plan of  exchange  in  which  Issuer  is
     acquired,  (iii) the Issuer in a merger or plan of exchange in which Issuer
     is the continuing or surviving or acquiring person, and (iv) the transferee
     of all or a substantial  part of Issuer's assets or deposits (or the assets
     or deposits of any Issuer Subsidiary).

          (ii)  "Substitute  Common Stock" shall mean the common stock issued by
     the issuer of the Substitute Option upon exercise of the Substitute Option.

          (iii) "Assigned Value" shall mean the  market/offer  price, as defined
     in Section 7.

          (iv) "Average  Price" shall mean the average  closing price of a share
     of the  Substitute  Common  Stock for one year  immediately  preceding  the
     consolidation,  merger or sale in question, but in no event higher than the
     closing price of the shares of Substitute Common Stock on the day preceding
     such  consolidation,  merger or sale; provided that if Issuer is the issuer
     of the Substitute  Option, the Average Price shall be computed with respect
     to a share of common stock  issued by the person  merging into Issuer or by
     any company which  controls or is controlled by such person,  as the Holder
     may elect.

         (c) Subject to paragraph (d) of this Section 8, the  Substitute  Option
shall  have the same  terms as the  Option,  provided  that if the  terms of the
Substitute  Option cannot,  for legal reasons,  be the same as the Option,  such
terms shall be as similar as possible and in no event less  advantageous  to the
Holder.  The issuer of the Substitute  Option shall also enter into an agreement
with the then Holder or Holders of the Substitute  Option in  substantially  the
same  form as this  Agreement  (after  giving  effect  for such  purpose  to the
provisions of Section 9), which  agreement shall be applicable to the Substitute
Option.

         (d) The  Substitute  Option  shall be  exercisable  for such  number of
shares of Substitute  Common Stock as is equal to the Assigned Value  multiplied
by the number of shares of Common  Stock for which the  Option  was  exercisable
immediately  prior to the event described in the first sentence of Section 8(a),
divided by the Average Price.  The exercise  price of the Substitute  Option per
share of  Substitute  Common  Stock  shall  then be equal  to the  Option  Price
multiplied  by a fraction,  the numerator of which shall be the number of shares
of Common Stock for which the Option was  exercisable  immediately  prior to the
event  described in the first  sentence of Section 8(a)

                                      -10-
<PAGE>

and the denominator of which shall be the number of shares of Substitute  Common
Stock for which the Substitute Option is exercisable.

         (e) In no event, pursuant to any of the foregoing paragraphs, shall the
Substitute Option be exercisable for more than 19.9% of the shares of Substitute
Common Stock  outstanding  prior to exercise of the  Substitute  Option.  In the
event that the Substitute Option would be exercisable for more than 19.9% of the
shares of  Substitute  Common Stock  outstanding  prior to exercise but for this
clause (e), the issuer of the Substitute Option (the "Substitute Option Issuer")
shall make a cash  payment to Holder equal to the excess of (i) the value of the
Substitute  Option  without  giving effect to the  limitation in this clause (e)
over  (ii)  the  value of the  Substitute  Option  after  giving  effect  to the
limitation in this clause (e). This difference in value shall be determined by a
nationally recognized investment banking firm selected by the Holder.

         (f) Issuer shall not enter into any transaction described in subsection
(a) of this  Section 8 unless the  Acquiring  Corporation  and any  person  that
controls the  Acquiring  Corporation  assume in writing all the  obligations  of
Issuer hereunder.

         9. (a) At the  request  of the  holder of the  Substitute  Option  (the
"Substitute Option Holder") occurring after a Substitute Option Repurchase Event
and  prior to the date  that is six (6)  months  thereafter,  the  issuer of the
Substitute  Option  (the  "Substitute   Option  Issuer")  shall  repurchase  the
Substitute  Option from the Substitute Option Holder at a price (the "Substitute
Option  Repurchase  Price") equal to the amount by which (i) the Highest Closing
Price (as hereinafter defined) exceeds (ii) the exercise price of the Substitute
Option,  multiplied by the number of shares of Substitute Common Stock for which
the  Substitute  Option may then be  exercised,  and at the request of the owner
(the  "Substitute  Share  Owner")  of shares of  Substitute  Common  Stock  (the
"Substitute  Shares"),   the  Substitute  Option  Issuer  shall  repurchase  the
Substitute Shares at a price (the "Substitute Share Repurchase  Price") equal to
the Highest  Closing  Price  multiplied  by the number of  Substitute  Shares so
designated.  The term  "Highest  Closing  Price" shall mean the highest  closing
price for  shares  of  Substitute  Common  Stock  within  the  one-month  period
immediately  preceding the date the Substitute Option Holder gives notice of the
required repurchase of the Substitute Option or the Substitute Share Owner gives
notice of the required repurchase of the Substitute Shares, as applicable.

         (b) The Substitute Option Holder and the Substitute Share Owner, as the
case may be, may exercise its respective rights to require the Substitute Option
Issuer to repurchase the Substitute Option and the Substitute Shares pursuant to
this Section 9 by surrendering for such purpose to the Substitute Option Issuer,
at its principal  office,  the agreement for such Substitute  Option (or, in the
absence of such an agreement,  a copy of this Agreement) and/or certificates for
Substitute  Shares  accompanied by a written notice or notices  stating that the
Substitute  Option  Holder or the  Substitute  Share Owner,  as the case may be,
elects to require the  Substitute  Option  Issuer to repurchase  the  Substitute
Option and/or the  Substitute  Shares in accordance  with the provisions of this
Section 9. As promptly as practicable and in any event within five business days
after the surrender of the Substitute  Option and/or  certificates  representing
Substitute  Shares and the receipt of such notice

                                      -11-
<PAGE>

or notices relating thereto, the Substitute Option Issuer shall deliver or cause
to be delivered to the Substitute Option Holder the Substitute Option Repurchase
Price and/or to the Substitute Share Owner the Substitute Share Repurchase Price
therefor or the portion  thereof which the Substitute  Option Issuer is not then
prohibited under applicable law and regulation from so delivering.

         (c) To the extent that the Substitute Option Issuer is prohibited under
applicable law or regulation, or as a consequence of administrative policy, from
repurchasing  the Substitute  Option and/or the Substitute  Shares in part or in
full,  the Substitute  Option Issuer shall  immediately so notify the Substitute
Option Holder and/or the Substitute Share Owner and thereafter  deliver or cause
to be delivered,  from time to time, to the Substitute  Option Holder and/or the
Substitute  Share Owner,  as appropriate,  the portion of the Substitute  Option
Repurchase  Price and/or the Substitute Share  Repurchase  Price,  respectively,
which it is no longer prohibited from delivering,  within ten (10) business days
after the date on which the Substitute Option Issuer is no longer so prohibited;
provided,  however,  that if the  Substitute  Option Issuer is at any time after
delivery of a notice of repurchase  pursuant to subsection (b) of this Section 9
prohibited  under  applicable  law  or  regulation,   or  as  a  consequence  of
administrative  policy,  from delivering to the Substitute  Option Holder and/or
the Substitute  Share Owner, as appropriate,  the Substitute  Option  Repurchase
Price and the Substitute Share Repurchase Price, respectively,  in full (and the
Substitute  Option Issuer shall use its best efforts to receive (and to take all
action  necessary  to receive) all required  regulatory  and legal  approvals as
promptly as practicable in order to accomplish such repurchase),  the Substitute
Option Holder and/or  Substitute Share Owner may revoke its notice of repurchase
of the  Substitute  Option or the  Substitute  Shares  either in whole or to the
extent of  prohibition,  whereupon,  in the latter case, the  Substitute  Option
Issuer shall promptly (i) deliver to the Substitute  Option Holder or Substitute
Share Owner, as appropriate,  that portion of the Substitute  Option  Repurchase
Price or the Substitute Share Repurchase Price that the Substitute Option Issuer
is not prohibited from delivering; and (ii) deliver, as appropriate,  either (A)
to the Substitute Option Holder, a new Substitute Option evidencing the right of
the Substitute Option Holder to purchase that number of shares of the Substitute
Common  Stock  obtained by  multiplying  the number of shares of the  Substitute
Common Stock for which the surrendered  Substitute Option was exercisable at the
time of delivery of the notice of  repurchase  by a fraction,  the  numerator of
which  is the  Substitute  Option  Repurchase  Price  less the  portion  thereof
theretofore  delivered to the  Substitute  Option Holder and the  denominator of
which is the Substitute Option  Repurchase  Price,  and/or (B) to the Substitute
Share  Owner,  a  certificate  for the  Substitute  Option  Shares it is then so
prohibited  from  repurchasing.  If an  Exercise  Termination  Event  shall have
occurred  prior  to the  date of the  notice  by the  Substitute  Option  Issuer
described in the first sentence of this subsection (c), or shall be scheduled to
occur at any time before the  expiration of a period ending on the thirtieth day
after such date, the Substitute Option Holder shall  nevertheless have the right
to exercise the Substitute Option until the expiration of such 30-day period.

         10. The 30-day,  6-month,  12-month,  18-month or 24-month  periods for
exercise  of  certain  rights  under  Sections  2, 6, 7, 9, 12 and 14  shall  be
extended: (i) to the extent necessary to obtain all regulatory approvals for the
exercise of such rights (for so long as the  Holder,  Owner,

                                      -12-
<PAGE>

Substitute Option Holder or Substitute Share Owner, as the case may be, is using
commercially  reasonable efforts to obtain such regulatory  approvals),  and for
the  expiration  of all  statutory  waiting  periods;  and  (ii)  to the  extent
necessary to avoid  liability  under  Section 16(b) of the 1934 Act by reason of
such exercise.

         11. Issuer hereby represents and warrants to Grantee as follows:

         (a) Issuer  has full  corporate  power and  authority  to  execute  and
deliver this Agreement and to consummate the transactions  contemplated  hereby.
The  execution  and  delivery  of this  Agreement  and the  consummation  of the
transactions  contemplated  hereby have been duly and validly  authorized by the
Issuer Board prior to the date hereof and no other corporate  proceedings on the
part of Issuer are necessary to authorize  this  Agreement or to consummate  the
transactions so contemplated.  This Agreement has been duly and validly executed
and delivered by Issuer.

         (b) Issuer has taken all  necessary  corporate  action to authorize and
reserve and to permit it to issue, and at all times from the date hereof through
the  termination  of this  Agreement  in  accordance  with its  terms  will have
reserved for issuance upon the exercise of the Option,  that number of shares of
Common  Stock equal to the maximum  number of shares of Common Stock at any time
and from time to time  issuable  hereunder,  and all such shares,  upon issuance
pursuant  thereto,  will  be  duly  authorized,   validly  issued,  fully  paid,
nonassessable,  and will be  delivered  free and  clear  of all  claims,  liens,
encumbrance and security interests and not subject to any preemptive rights.

         12.  Neither  of the  parties  hereto  may  assign any of its rights or
obligations  under this Agreement or the Option  created  hereunder to any other
person,  without the express written consent of the other party,  except that in
the event an Initial  Triggering  Event shall have occurred prior to an Exercise
Termination Event, Grantee, subject to the express provisions hereof, may assign
in whole or in part its rights and  obligations  hereunder;  provided,  however,
that  until the date 15 days  following  the date on which  the OTS and  Federal
Reserve Board has approved, to the extent required, an application by Grantee to
acquire the shares of Common Stock subject to the Option, Grantee may not assign
its  rights  under  the  Option  except  in  (i)  a  widely   dispersed   public
distribution,  (ii) a private placement in which no one party acquires the right
to purchase in excess of 2% of the voting shares of Issuer,  (iii) an assignment
to a single  party  (e.g.,  a broker or  investment  banker)  for the purpose of
conducting a widely  dispersed  public  distribution on Grantee's behalf or (iv)
any other manner approved by the Federal Reserve Board.

         13.  Each of Grantee and Issuer  will use its  commercially  reasonable
efforts to make all filings with,  and to obtain  consents of, all third parties
and governmental  authorities  necessary to the consummation of the transactions
contemplated by this Agreement,  including, without limitation,  applying to the
Federal  Reserve  Board  under the BHCA and the OTS under  HOLA,  to the  extent
required,  for approval to acquire the shares  issuable  hereunder,  but Grantee
shall not be obligated to apply to state banking authorities for approval to

                                      -13-
<PAGE>

acquire the shares of Common Stock issuable  hereunder until such time, if ever,
as it deems appropriate to do so.

         14. (a) Grantee may, at any time following a Repurchase Event and prior
to the  occurrence  of an Exercise  Termination  Event (or such later  period as
provided in Section 10),  relinquish the Option (together with any Option Shares
issued to and then owned by Grantee) to Issuer in exchange  for a cash fee equal
to the Surrender  Price;  provided,  however,  that Grantee may not exercise its
rights  pursuant to this Section 14 if Issuer has repurchased the Option (or any
portion  thereof) or any Option  Shares  pursuant  to Section 7. The  "Surrender
Price" shall be equal to $9,000,000 (i) plus, if applicable,  Grantee's purchase
price with respect to any Option Shares purchased by Grantee  hereunder and (ii)
minus, if applicable,  the sum of (1) the excess of (A) the net cash amounts, if
any,  received by Grantee pursuant to the arms' length sale of Option Shares (or
any other  securities into which such Option Shares were converted or exchanged)
to any  unaffiliated  party,  over (B) Grantee's  purchase  price of such Option
Shares, and (2) the net cash amounts, if any, received by Grantee pursuant to an
arms' length sale of any portion of the Option sold.

         (b) Grantee may  exercise  its right to  relinquish  the Option and any
Option  Shares  pursuant to this Section 14 by  surrendering  to Issuer,  at its
principal office, a copy of this Agreement together with certificates for Option
Shares, if any,  accompanied by a written notice stating (i) that Grantee elects
to  relinquish  the Option and Option  Shares,  if any, in  accordance  with the
provisions of this Section 14 and (ii) the Surrender  Price. The Surrender Price
shall be payable in immediately available funds on or before the fifth business
day following receipt of such notice by Issuer.

         (c) To the extent that Issuer is  prohibited  under  applicable  law or
regulation,  or as a  consequence  of  administrative  policy,  from  paying the
Surrender Price to Grantee in full,  Issuer shall  immediately so notify Grantee
and thereafter deliver or cause to be delivered,  from time to time, to Grantee,
the portion of the Surrender Price that it is no longer  prohibited from paying,
within ten (10)  business  days  after the date on which  Issuer is no longer so
prohibited;  provided,  however,  that if Issuer at any time after delivery of a
notice of surrender  pursuant to paragraph  (b) of this Section 14 is prohibited
under  applicable  law or  regulation,  or as a  consequence  of  administrative
policy, from paying to Grantee the Surrender Price in full, (i) Issuer shall (A)
use its best efforts to obtain (and to take all action  necessary to obtain) all
required  regulatory  and legal  approvals  and to file any required  notices as
promptly as practicable in order to make such payments,  (B) within five days of
the submission or receipt of any documents  relating to any such  regulatory and
legal  approvals,  provide Grantee with copies of the same, and (c) keep Grantee
advised  of both the  status  of any  such  request  for  regulatory  and  legal
approvals,  as well as any  discussions  with any relevant  regulatory  or other
third  party  reasonably  related to the same and (ii)  Grantee  may revoke such
notice of surrender by delivery of a notice of  revocation  to Issuer and,  upon
delivery of such notice of revocation,  the Exercise  Termination  Date shall be
extended  to a date six months from the date on which the  Exercise  Termination
Date would have occurred if not for the provisions of this Section 14(c) (during
which period Grantee may exercise any of its rights hereunder, including any and
all rights pursuant to this Section 14).

                                      -14-

<PAGE>


         15. The parties hereto  acknowledge that damages would be an inadequate
remedy  for a breach of this  Agreement  by  either  party  hereto  and that the
obligations  of the parties  hereto shall be  enforceable by either party hereto
through  injunctive or other  equitable  relief.  In connection  therewith  both
parties waive the posting of any bond or similar requirement.

         16. If any term,  provision,  covenant or restriction contained in this
Agreement  is held  by a court  or a  federal  or  state  regulatory  agency  of
competent  jurisdiction to be invalid,  void or unenforceable,  the remainder of
the terms, provisions and covenants and restrictions contained in this Agreement
shall remain in full force and effect, and shall in no way be affected, impaired
or  invalidated.  If for any reason such court or regulatory  agency  determines
that the Holder is not  permitted  to  acquire,  or Issuer is not  permitted  to
repurchase  pursuant  to  Section 7, the full  number of shares of Common  Stock
provided in Section l(a) hereof (as adjusted pursuant to Section l(b) or Section
5 hereof),  it is the express intention of Issuer to allow the Holder to acquire
or to  require  Issuer  to  repurchase  such  lesser  number of shares as may be
permissible, without any amendment or modification hereof.

         17. All notices,  requests,  claims,  demands and other  communications
hereunder  shall be deemed to have been duly given when delivered in person,  by
fax,  telecopy,  or by registered or certified  mail  (postage  prepaid,  return
receipt  requested) at the respective  addresses of the parties set forth in the
Merger Agreement.

         18. This  Agreement  shall be governed by and  construed in  accordance
with the laws of the State of New York,  without  regard to the  conflict of law
principles  thereof  (except to the extent that mandatory  provisions of Federal
law are applicable).

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

         20. Except as otherwise  expressly provided herein, each of the parties
hereto shall bear and pay all costs and expenses incurred by it or on its behalf
in connection with the transactions  contemplated hereunder,  including fees and
expenses of its own financial consultants,  investment bankers,  accountants and
counsel.

         21.  Except as  otherwise  expressly  provided  herein or in the Merger
Agreement, this Agreement contains the entire agreement between the parties with
respect to the  transactions  contemplated  hereunder and  supersedes  all prior
arrangements or understandings with respect thereof,  written or oral. The terms
and  conditions of this  Agreement  shall inure to the benefit of and be binding
upon the parties hereto and their respective successors and permitted assignees.
Nothing in this Agreement,  expressed or implied, is intended to confer upon any
party, other than the parties hereto, and their respective  successors except as
assignees, any rights,  remedies,  obligations or liabilities under or by reason
of this Agreement, except as expressly provided herein.


                                      -15-
<PAGE>


         22.  Capitalized  terms used in this  Agreement and not defined  herein
shall have the meanings assigned thereto in the Merger Agreement.

         IN WITNESS WHEREOF, each of the parties has caused this Agreement to be
executed on its behalf by its officers thereunto duly authorized,  all as of the
date first above written.


                                       Queens County Bancorp, Inc.


                                       By: /s/ Joseph R. Ficalora
                                          ---------------------------------
                                          Joseph R. Ficalora
                                          Chairman of the Board, President and
                                          Chief Executive Officer




                                       Haven Bancorp, Inc.


                                       By: /s/ Phillip S. Messina
                                          --------------------------------
                                          Phillip S. Messina
                                          Chairman of the Board
                                          and Chief Executive Officer

                                      -16-