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                                                                   EXHIBIT 23(F)
 
                        CONSENT OF FOX-PITT, KELTON INC.
 
UST Corp.
40 Court Street
Boston, Massachusetts 02108
 
Ladies and Gentlemen:
 
     We hereby consent to the use of our written opinion letter dated as of the
date of this Joint Proxy Statement - Prospectus to the Board of Directors of UST
Corp. included as Appendix D to the Joint Proxy Statement - Prospectus which
forms a part of the Registration Statement on Form S-4 relating to the proposed
merger of a wholly-owned subsidiary of UST Corp. with and into Walden Bancorp,
Inc. and to the references to such opinion, to our August 29, 1996 oral and
written opinion provided to the Board of Directors of UST Corp. and to this firm
in the Joint Proxy Statement - Prospectus. In giving such consent, we do not
admit that we come within the category of persons whose consent is required
under Section 7 of the Securities Act of 1933, as amended, or the rules and
regulations of the Securities and Exchange Commission thereunder, nor do we
admit that we are experts with respect to any part of such Registration
Statement within the meaning of the term "experts" as used in the Securities Act
of 1933, as amended, or the rules and regulations of the Securities and Exchange
Commission thereunder.
 
                                            FOX-PITT, KELTON INC.
 
                                            By: /s/  PETER E. ROTH
                                              ----------------------------------
                                              Name: Peter E. Roth
                                              Title:   Managing Director
 
November 5, 1996