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                            [UST Corp. letterhead]
                                                                 EXHIBIT 10(s)
                                March 31, 1994

Mr. William C. Brooks
39 Oak Hill Rd.
Wayland, MA 01778

Dear Bill:

        As we have discussed and agreed, your employment with UST Corp. and
its affiliated companies (collectively "UST") will terminate on July 31, 1994
and you will be paid through UST's payroll system through that date. The
purpose of this letter agreement is to set forth the terms and conditions
related to your separation from UST.

1.      Your last regularly scheduled day in the bank will be March 31, 1994.
        Thereafter, you will make yourself available at all such times as
        needed and as requested by the CEO and will remain and perform the
        duties of Chief Financial Officer of UST Corp. and Chief Accounting
        Officer of USTrust until July 31, 1994 or until another CFO is hired,
        whichever is first. Except as provided above, your resignation from
        all offices and directorships (including offices, directorships and
        committee memberships with UST Corp. and its subsidiaries) is
        effective as of March 31, 1994.

2.      Salary continuation: Salary will continue for 21 months after July 31,
        1994. The form of payment will be in one lump sum of $274,706 payable
        to you during the first week of August 1994.

        In addition, $15,000 will be added to this lump sum payment to assist
        with the cost of medical insurance, and $20,000 to provide
        outplacement services will be in this lump sum payment. This total
        lump sum amount is subject to applicable tax withholding.

        Should you die before July 31, 1994, your wife will receive in full
        satisfaction of this Agreement a sum equal to the amounts described in
        this Section 2.

3.      Continuation of benefits: UST will continue to pay the premiums for
        your group term life coverage through July 31, 1994.  Thereafter, if
        coverage is to continue, you will have to convert the coverage to an
        individual contract at your expense.

        Disability insurance provided through USTrust will cease as of July
        31, 1994.

        Medical insurance premiums will continue to be paid to provide coverage
        for you under the family Baystate Health Care plan through July 31, 
        1994.  During this period, you will continue to 

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        pay normal monthly employee contributions of $128 65.  Effective 
        August 1, 1994, you will be able to continue medical insurance 
        coverage through COBRA for up to 18 months.

4.      Vested profit sharing: You will be paid the account balance credited
        to you under the company's profit sharing plan after the 6/30/94
        valuation. It is understood that as of 6/30/93 your vested balance was
        $363,535.44. It is further understood that at the time of the
        valuation and payout, these amounts may be higher or lower depending
        on the valuation.

5.      Vested ESOP: You will be paid out the value of your vested ESOP
        account after the 6/30/94 valuation. It is understood that as of
        6/30/93 your vested balance was 11,074.3837 shares plus a cash balance
        of $122.81. It is further understood that at the time of the valuation
        and payout, these amounts may be higher or lower depending on the
        valuation.

6.      It is understood that you are 100% vested in the UST qualified
        retirement plan. A schedule has been provided to you indicating the
        projected pay-out amounts at age 65.

7.      Incentive stock options: Prior to March 15, 1994, you were vested in
        6,720 options. It is understood that vesting in the additional 1,680
        options was accelerated on March 15, 1994, so that at present, you are
        fully vested in 8,400 options at a price of $6.0714. Your options
        expire 3 months after July 31, 1994.

        It is further understood that as an Executive Officer of UST Corp.
        there are limitations on your ability to sell shares of UST Corp.
        stock. Shares must be held for six months after the date of
        termination (i.e. after 1/31/95) at which time you will cease to be
        deemed an Executive Officer of UST Corp.

8.      The above matter was presented to the UST Corp. Board of Directors on
        March 15, 1994 and was preliminarily approved.  Pending a third party
        certification by The Wyatt Co. and a definitive vote scheduled for
        April 19, 1994 of Board approval based upon the Wyatt certificate, the
        above matters will be subject only to the written approval of the
        Federal Reserve Bank of Boston and the Massachusetts Commissioner of
        Banks.

9.      Attached to this letter agreement as EXHIBIT A is a General and
        Specific Release signed by you which releases UST Corp. and its
        successors, assigns, subsidiaries, and its and their respective
        officers, directors, employees, agents and representatives from
        various liabilities and claims. The foregoing Release, attached
        as EXHIBIT A, is incorporated into this letter agreement and made a
        part hereof.


If the foregoing is agreeable to you and you wish to accept the terms and
conditions of this letter agreement, please indicate your assent and agreement
by signing this letter agreement below and 

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by attaching a signed and notarized copy of EXHIBIT A.

                                  Very truly yours,



                                  /s/ Neal F. Finnegan
                                  --------------------
                                  Neal F. Finnegan
                                  President and Chief Executive Officer
                                  UST Corp.


ACCEPTED AND AGREED:


/s/ William C. Brooks
---------------------
William C. Brooks

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Exhibit A

General and Specific Release

FOR AND IN CONSIDERATION of payments to be made to me in connection with my
separation of employment, as set out in the Separation Agreement between UST
Corp. and me, dated March 31, 1994, I, William C. Brooks, hereby release UST
Corp. ("UST") and its successors, assigns, subsidiaries and its and their
respective officers, directors, employees, agents and representatives (all
collectively, "Releases") from any and all liability, claims, demands,
actions, causes of action of any type by reason of any matter, cause, act or
omission arising out of or in connection with my employment or separation from
employment with UST Corp. and/or its subsidiaries, including without
limitation, claims, demands or actions under Title VII of Civil Rights Act of
1964, as amended, the Rehabilitation Act of 1973, the Civil Rights Act of 1866,
the Massachusetts Fair Employment Practices Act, and any other Federal, state
or local statute or regulation regarding employment, discrimination in
employment or termination of employment; and I, William C. Brooks, shall at no
time take any action that I am aware is inconsistent with this Release;
provided that I am not releasing and shall not be deemed to have released (i)
any claim arising under the terms of the Separation Agreement or the terms of
UST's employee pension plan, profit sharing plan, or stock ownership plan,
each as amended to the effective time of my termination of employment, or (ii)
any right of indemnification or contribution that may exist at or may arise
after such effective time and that I am or may be entitled to enforce against
UST if any claim is asserted or proceedings are brought against me by any
governmental or regulatory agency, or by any customer, creditor, employee or
shareholder of UST, or any self-regulatory organization, stock exchange or the
like, related or allegedly related to my having been an officer or employee of
UST, or to any of my activities as an officer or employee of UST. By
acceptance of or reliance upon this Release, UST promises that neither it nor
any other of the Releases affiliated with UST, will take any action that is
designed, specifically with respect to me or with respect to a class of
similarly situated former employees, to reduce or abrogate, or may reasonably
be expected to result in an abridgement or elimination of, any rights of
indemnification or contribution available to me under state law or pursuant to
the Articles of Organization or Bylaws of UST, or under any policy or policies
of directors and officers liability insurance affording coverage to former
officers and in effect from time to time.

IN WITNESS WHEREOF, I, William C. Brooks, have set my and seal this 31st day of
March, 1994.


/s/ William C. Brooks