EXHIBIT (a)(4)



                                LETTER TO BROKERS

                           OFFER TO PURCHASE FOR CASH

                  All of the Outstanding Shares of Common Stock

                                       of

                              COHOES BANCORP, INC.

                                       at

                              $16.50 Net Per Share

                                       by

                            AMBANC HOLDING CO., INC.


THE OFFER AND  WITHDRAWAL  RIGHTS WILL EXPIRE AT 12:00  MIDNIGHT,  NEW YORK CITY
TIME, ON WEDNESDAY, SEPTEMBER 6, 2000, UNLESS THE OFFER IS EXTENDED.


                                                                  August 9, 2000

To Brokers, Dealers, Commercial Banks,
Trust Companies and Other Nominees:

         Ambanc  Holding  Co.,  Inc.,  a  Delaware  corporation  ("Ambanc"),  is
offering to purchase all of the  outstanding  shares of common stock,  par value
$.01 per share (the "Shares"),  of Cohoes Bancorp,  Inc., a Delaware corporation
("Cohoes"),  at $16.50 per Share,  net to the seller in cash,  without  interest
thereon,  upon the terms and subject to the conditions set forth in the Offer to
Purchase  dated  August 9, 2000 (the  "Offer to  Purchase")  and in the  related
Letter of Transmittal (which together constitute the "Offer") enclosed herewith.

         Holders of Shares whose  certificates for such Shares  ("Certificates")
are not immediately available or who cannot deliver their Certificates,  and all
other required  documents to the Depositary on or prior to the expiration of the
Offer ("Expiration  Date"), or who cannot complete the procedures for book-entry
transfer on a timely basis, must tender their Shares according to the guaranteed
delivery procedures set forth in Section 4 of the Offer to Purchase.

         Please  furnish  copies  of the  enclosed  materials  to  those of your
clients for whose  accounts  you hold Shares  registered  in your name or in the
name of your nominee.

         THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS,  THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN  PRIOR TO THE  EXPIRATION OF THE OFFER THAT NUMBER OF
SHARES WHICH,  TOGETHER WITH SHARES BENEFICIALLY OWNED BY AMBANC,  REPRESENTS AT
LEAST A MAJORITY OF THE SHARES  OUTSTANDING ON A FULLY DILUTED BASIS ON THE DATE
OF PURCHASE. CERTAIN OTHER CONDITIONS TO CONSUMMATION OF THE OFFER ARE DESCRIBED
IN SECTION 12 OF THE OFFER TO PURCHASE.  AMBANC EXPRESSLY  RESERVES THE RIGHT TO
WAIVE ANY ONE OR MORE OF THE CONDITIONS OF THE OFFER.








         Enclosed  herewith  for your  information  and for  forwarding  to your
clients for whose  accounts  you hold Shares  registered  in your name or in the
name of your nominee are copies of the following documents:

          1.   The Offer to Purchase dated August 9, 2000;

          2.   The Letter of Transmittal for your use and for the information of
               your clients.  Facsimile  copies of the Letter of Transmittal may
               be used to tender Shares;

          3.   A Notice of Guaranteed Delivery to be used to accept the Offer if
               certificates for Shares are not immediately  available or if such
               certificates and all other required documents cannot be delivered
               to the  Depositary  before the  expiration of the Offer or if the
               procedures  for  book-entry  transfer  cannot be  completed  on a
               timely basis;

          4.   A printed  form of letter  which may be sent to your  clients for
               whose  account you hold Shares  registered in your name or in the
               name of your  nominee,  with space  provided for  obtaining  such
               clients' instructions with regard to the Offer;

          5.   Guidelines of the Internal  Revenue Service for  Certification of
               Taxpayer Identification Number on Substitute Form W-9; and

          6.   A return envelope addressed to the Depositary.

         YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS AS
PROMPTLY  AS  POSSIBLE.  THE OFFER AND  WITHDRAWAL  RIGHTS  WILL EXPIRE AT 12:00
MIDNIGHT, NEW YORK CITY TIME, ON WEDNESDAY,  SEPTEMBER 6, 2000, UNLESS THE OFFER
IS EXTENDED.

         In  order  to  accept  the  Offer,  (i) a duly  executed  and  properly
completed  Letter of Transmittal with any required  signature  guarantees or any
Agent's  Message (as defined in the Offer to Purchase),  or other  documentation
should be sent to the Depositary,  and (ii) either certificates representing the
tendered  Shares should be delivered to the  Depositary or such Shares should be
tendered by book-entry transfer into the Depositary's  account maintained at one
of the Book-Entry Transfer Facilities (as defined in the Offer to Purchase), all
in accordance with the  instructions  set forth in the Letter of Transmittal and
the Offer to Purchase.

         If holders of Shares wish to tender,  but it is impractical for them to
forward their certificates for such Shares or other required documentation on or
prior to the expiration of the Offer or to comply with the  book-entry  transfer
procedures  on a timely  basis,  a  tender  may be  effected  by  following  the
guaranteed delivery procedures  specified in Section 4 of the accompanying Offer
to Purchase.

         Ambanc will not pay any  commissions  or fees to any broker,  dealer or
other person (other than to D.F. King & Co.,  Inc., as described in the Offer to
Purchase) for soliciting  tenders of Shares pursuant to the Offer.  Ambanc will,
however, upon request, reimburse you for customary clerical and mailing expenses
incurred by you in  forwarding  any of the enclosed  materials to your  clients.
Ambanc  will pay or cause to be paid any stock  transfer  taxes  payable  on the
transfer  of  Shares,  except as  otherwise  provided  in  Instruction  6 of the
enclosed Letter of Transmittal.

         Any questions or requests for assistance may be directed to D.F. King &
Co., Inc. at the address and telephone number set forth on the back cover of the
Offer to Purchase.  Requests for additional copies of the Offer to Purchase, the
Letter of Transmittal  and other tender offer  materials may be directed to D.F.
King & Co., Inc. or to brokers, dealers, commercial banks or trust companies.