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                                                                     Exhibit 5.1

               [PATTERSON, BELKNAP, WEBB & TYLER LLP LETTERHEAD]


                                 March 26, 1999

Dime Bancorp, Inc.
589 Fifth Avenue
New York, New York 10017

Dear Sirs:

     As set forth in the Registration Statement on Form S-8 ("Registration 
Statement") proposed to be filed by Dime Bancorp, Inc. (the "Company") on 
March 26, 1999 under the Securities Act of 1933, as amended, relating to 
975,000 shares (the "Shares") of common stock, par value $.01 per share, of the 
Company to be issued pursuant to the Dime Bancorp, Inc. Pride Shares Program 
(the "Plan"), certain legal matters in connection with the Shares offered 
pursuant to the Plan are being passed upon for the Company by this firm. At 
your request, this opinion of counsel is being furnished to you for filing with 
the Registration Statement.

     In our capacity as counsel in this connection, we have familiarized 
ourselves with the Amended and Restated Certificate of Incorporation and 
Bylaws, each as amended to date, of the Company and have examined the 
originals, or copies certified or otherwise identified, of the Plan, corporate 
records of the Company, certificates of public officials and representatives of 
the Company, statutes and other instruments and documents as the basis for the 
opinion hereinafter expressed.

     On the basis of the foregoing, we are of the opinion that the Shares, when
issued and sold pursuant to the provisions of the Plan for a consideration at
least equal to the par value of the Shares, will be duly authorized, validly
issued, fully paid and nonassessable.

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March 26, 1999
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     We hereby consent to the filing of this opinion letter with the 
Registration Statement.

                                   PATTERSON, BELKNAP, WEBB & TYLER LLP
     

                                   By: /s/ Douglas E. Barzelay
                                       -------------------------------
                                       Douglas E. Barzelay