<PAGE>   1
                               EXHIBIT (c)(10)(g)
                              EMPLOYMENT AGREEMENT

         THIS EMPLOYMENT AGREEMENT (the "Agreement"), made as of this 14th day
of November, 1996, is entered into by Portsmouth Savings Bank (the "Bank") and
Portsmouth Bank Shares, Inc. (the "Corporation"), New Hampshire corporations
with their principal place of business at Portsmouth, New Hampshire, and JOHN J.
PRATT, JR. (the "Employee").

         The Bank desires to employ the Employee and the Employee desires to be
employed by the Bank. In consideration of the mutual covenants and premises
contained herein, and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged by the parties hereto, the parties
agree as follows:

         1. Term of Employment. The Bank hereby agrees to employ the Employee,
and the Employee hereby accepts employment with the Bank, upon the terms set
forth in this Agreement, for a period of one year commencing on November 14,
1996 (the "Commencement Date"). This Agreement will automatically be extended
for a term of one year on each yearly anniversary of the date of execution of
this Agreement unless prior thereto any party gives written notice otherwise to
the other party or parties. If a Change of Control (as defined below) takes
place, the expiration date of the Agreement shall automatically be extended to
the first yearly anniversary of the date on which such Change of Control occurs
and shall be automatically extended for a term of one year on each yearly
anniversary of this Agreement after the date on which such Change of Control
occurs unless prior thereto any party gives written notice otherwise to the
other party or parties. Thus, by way of example only, if a Change of Control
were to occur on August 1, 1997, and the term of this Agreement was otherwise to
have expired on November 14, 1997, it shall instead expire on August 1, 1998,
subject to one-year extensions as aforesaid. This Agreement shall continue in
force throughout the term described above unless sooner terminated in accordance
with the provisions of Section 4. A Change of Control is defined as occurring
when: (i) any "person" (as such term is used in Sections 13(d) and 14(d) of the
Securities Exchange Act of 1934, as amended ("Exchange Act"), other than the
Corporation or the Bank is or becomes the "beneficial owner" (as defined in Rule
13d-3 under the Exchange Act), directly or indirectly, of securities of the
Corporation or the Bank representing 20% or more of the combined voting power of
the then outstanding securities of the Corporation or the Bank; or (ii) there is
a change in the composition of the Board of Directors of the Corporation or the
Bank so that less than a majority of the Board shall be (x) persons who shall
have been


                                        1
<PAGE>   2
members thereof for more than 36 months or (y) persons whose election or
nomination for election was approved by at least two-thirds of the directors
then still in office who either were directors at the beginning of such 36-month
period or whose election or nomination was previously so approved (persons
described in clauses (x) and (y) above are hereinafter referred to as
"Continuing Directors") or (iii) the Corporation or the Bank is party to a
merger or consolidation and neither the Corporation nor the Bank is the
surviving entity; or (iv) the Corporation or the Bank is a party to a merger or
consolidation following which the voting securities of the corporation or the
Bank (as the case may be) outstanding immediately prior thereto do not continue
to represent at least 80% of the combined voting power of the surviving
corporation in such merger or consolidation; or (v) there has been a change in
ownership of a substantial portion of the assets of the corporation or the Bank
or (vi) the stockholders of the Corporation or the Bank approve a plan of
complete liquidation of such corporation.

         2. Title: Capacity. The Employee shall serve the Bank as a Senior Vice
President or in such other higher position as the Board of Directors (the
"Board") may determine from time to time. The Employee shall be subject to the
supervision of, and shall have such authority as is delegated to him by, the
Chairman of the Board and the President of either corporation.

         The Employee hereby accepts such employment and agrees to undertake the
duties and responsibilities inherent in such position and such other duties and
responsibilities as the Board or its designee shall from time to time reasonably
assign to him. The Employee agrees to devote his entire business time, attention
and energies to the business and interests of the Bank during the Employment
Period, and his office shall be located at all times in Portsmouth, New
Hampshire. The Employee agrees to abide by the rules, regulations, instructions,
personnel practices and policies of the Bank and any changes therein which may
be adopted from time to time by the Bank, subject to the provisions of Section
4.5 below.

         3. Compensation and Benefits.

                  3.1 Salary. The Bank shall pay the Employee, in weekly
installments, an annual base salary equal to the Employee's annual base salary
as in effect on the day prior to the Commencement Date. Such salary shall be
subject to adjustment thereafter as determined by the Board, unless there is a
Change of Control as defined in Section 1 and then in no case during the
one-year term of this Agreement from and after such Change of Control provided
for in Section 1 shall the compensation (defined as total salary


                                        2
<PAGE>   3
and cash bonus) of the Employee be reduced below the compensation paid the
Employee for the fiscal year immediately preceding the fiscal year in which such
Change of Control occurs (the "Prior Compensation") without the mutual consent
of the parties.

                  3.2 Fringe Benefits. The Employee shall be entitled to
participate in any and all bonus and benefit programs that the Bank establishes
and makes available to its employees and officers, to the extent that Employee's
position, tenure, salary, age, health and other qualifications make him eligible
to participate. The Employee shall be entitled to such weeks of paid vacation
per year, not less than three, as is determined by and at such times as may be
approved by the Chairman of the Board and the President of either corporation.

                  3.3 Reimbursement of Expenses. The Bank shall reimburse the
Employee for all reasonable travel, entertainment and other expenses incurred or
paid by the Employee in connection with, or related to, the performance of his
duties, responsibilities or services under this Agreement, upon presentation by
the Employee of documentation, expense statements, vouchers and/or such other
supporting information as the Bank may request, provided, however, that the
amount available for such travel, entertainment and other expenses may be fixed
in advance by the Chairman of the Board and the President of either corporation.

         4. Employment Termination. The employment of the Employee by the Bank
and the Corporation pursuant to this agreement shall terminate upon the
occurrence of any of the following:

                  4.1 At the election of the Bank, for cause, immediately upon
written notice by the Bank to the Employee. For the purposes of this Section
4.1, cause for termination shall be deemed to exist upon (a) a good faith
finding by the Bank of dishonesty, gross negligence or misconduct, or (b) the
conviction of the Employee of, or the entry of a pleading of guilty or nolo
contendere by the Employee to, any crime involving moral turpitude or any felony
or (c) a good faith finding by the Bank, made prior to any Change of Control, of
failure of the Employee to perform his assigned duties for the Bank.

                  4.2 Thirty days after the death or disability of the Employee.
As used in this Agreement, the term "disability" shall mean the inability of the
Employee, due to a physical or mental disability, for a period of 90 days,
whether or not consecutive, during any 360-day period to perform the services
contemplated under this Agreement. A determination of disability shall be made
by a physician satisfactory to both the Employee and the Bank,


                                        3
<PAGE>   4
provided that if the Employee and the Bank do not agree on a physician, the
Employee and Bank shall each select a physician and these two together shall
select a third physician, whose determination as to disability shall be binding
on all parties.

                  4.3 At the election of the Bank or the Corporation, without
cause, immediately upon written notice by the Bank to the Employee pursuant to
Section 8.

                  4.4 At the election of the Employee, without cause, with not
less than three months' prior written notice of such election.

                  4.5 At the election of the Employee, effective immediately,
for Good Reason following a Change of Control. Good Reason is defined to mean
the occurrence of any of the following events: (i) the assignment to the
Employee of any duties inconsistent with the position in the Corporation and the
Bank that he held immediately prior to the Change of Control, or a significant
adverse alteration in the nature or status of his responsibilities or the
conditions of his employment with the Corporation or the Bank from those in
effect immediately prior to such Change of Control; (ii) the relocation of the
office at which the Employee is principally employed to a location outside
Portsmouth, New Hampshire, or the Corporation's or the Bank's requiring the
Employee to engage in travel on the business of the Corporation and the Bank to
an extent substantially inconsistent with his previous business travel
obligations; (iii) any reduction in the Employee's compensation and benefits, or
any failure to make full and prompt payment of all compensation and benefits
owing to the Employee; or (iv) any other material breach of any of the terms and
conditions of this Agreement.

         5. Effect of Termination.

                  5.1 Termination for Cause or by the Employee without Good
Reason. In the event the Employee's employment is terminated for cause pursuant
to Section 4.1, or by the Employee without cause pursuant to Section 4.4, the
Bank shall pay to the Employee the compensation and benefits otherwise payable
to him under Section 3 through the last day of his actual employment by the
Bank.

                  5.2 Termination for Death or Disability. If the Employee's
employment is terminated by death or because of disability pursuant to Section
4.2, the Bank shall pay to the estate of the Employee or to the Employee, as the
case may be, the compensation which would otherwise be payable to the Employee
up


                                        4
<PAGE>   5
to the end of the month in which the termination of his employment because of
death or disability occurs.

                  5.3 Termination Without Cause or by the Employee for Good
Reason. If the Employee's employment is terminated by the Bank without cause
pursuant to Section 4.3, or by the Employee for Good Reason following a Change
of Control pursuant to Section 4.5, the Bank shall pay to the Employee, within
ten days of termination, an amount of cash equal to the product of one times the
Employee's annual compensation during the year immediately prior to the date of
termination.

                  5.4 Survival. The provisions of Section 6 and 7 shall survive
the termination of this Agreement.

         6. Non-Compete.

                  (a) During the Employment Period, and for a period of six (6)
months after the termination of this Agreement by the Employee (except by the
Employee for Good Reason following a Change of Control pursuant to Section 4.5),
the Employee will not directly or indirectly:

                           (i) as an individual proprietor, partner,
stockholder, officer, employee, director, joint venturer, investor, lender, or
in any other capacity whatsoever (other than as the holder of not more than one
percent (1%) of the total outstanding stock of a publicly held company), engage
in any business competitive with the business of the Bank that has a business
presence within ten (10) miles of the main office of the Bank or a branch of the
Bank; or

                           (ii) recruit, solicit or induce, or attempt to
induce, any employee or employees of the Bank to terminate their employment with
or otherwise cease their relationship with, the Bank; or

                           (iii) solicit, divert or take away, or attempt to
divert or to take away, the business or patronage of any of the clients,
customers or accounts, or prospective clients, customers or accounts, of the
Bank which were contacted, solicited or served by the Employee while employed by
the Bank.

                  (b) The restrictions contained in this Section 6 are necessary
for the protection of the business and goodwill of the Bank and are considered
by the Employee to be reasonable for such purpose. The Employee agrees that any
breach of this Section 6 will cause the Bank substantial or irrevocable damage
and therefore, in the event of any such breach, in addition to such


                                        5
<PAGE>   6
other remedies which may be available, the Bank shall have the right to seek
specific performance and injunctive relief.

         7. Proprietary Information and Developments.

                  7.1 Proprietary Information.

                  (a) The Employee agrees that all information and know-how,
whether or not in writing, of a private, secret or confidential nature
concerning the Bank's and the Corporation's business or financial affairs
(collectively, "Proprietary Information") is and shall be the exclusive property
of the Bank and the Corporation. By way of illustration, but not limitation,
Proprietary Information may include products, processes, methods, projects,
developments, plans, research data, financial data, personnel data, computer
programs, and customer lists. The Employee will not disclose any Proprietary
Information to others outside the Bank and the Corporation or use the same for
any unauthorized purposes without written approval by an officer of the Bank or
the Corporation, either during or after his employment, unless and until such
Proprietary Information has become public knowledge without fault on the part of
the Employee.

                  (b) The Employee agrees that all files, letters, memoranda,
reports, records, data, program listings, or other written, photographic, or
other tangible material containing Proprietary Information, whether created by
the Employee or others, which shall come into his custody or possession, shall
be and are the exclusive property of the Bank and the Corporation to be used by
the Employee only in the performance of his duties for the Bank and Corporation.

                  (c) The Employee agrees that his obligation not to disclose or
use information, know-how and records of the types set forth in paragraphs (a)
and (b) above, also extends to such types of information, know-how, records and
tangible property of customers of the Bank or the Corporation or suppliers to
the Bank or the Corporation or other third parties who may have disclosed or
entrusted the same to the Bank or to the Employee in the course of the Bank's
business.

                  7.2 Other Agreements. The Employee hereby represents that he
is not bound by the terms of any agreement with any previous employer or other
party to refrain from using or disclosing any trade secret or confidential or
proprietary information in the course of his employment with the Bank or to
refrain from competing, directly or indirectly, with the business of such
previous employer or any other party. The Employee further represents that his
performance of all the terms of this


                                        6
<PAGE>   7
Agreement and as an employee of the Bank does not and will not breach any
agreement to keep in confidence proprietary information, knowledge or data
acquired by him in confidence or in trust prior to his employment with the Bank.

         8. Notices. All notices required or permitted under this Agreement
shall be in writing and shall be deemed effective upon personal delivery or upon
deposit in the United States Post Office, by registered or certified mail,
postage prepaid, addressed to either party at the Portsmouth Savings Bank, P.O.
Box 29, Portsmouth, New Hampshire.

         9. Pronouns. Whenever the context may require, any pronouns used in
this Agreement shall include the corresponding masculine, feminine or neuter
forms, and the singular forms of nouns and pronouns shall include the plural,
and vice versa.

         10. Entire Agreement. This Agreement constitutes the entire agreement
among the parties and supersedes all prior agreements and understandings,
whether written or oral, relating to the subject matter of this Agreement.

         11. Amendment. This Agreement may be amended or modified only by a
written instrument executed by the Bank, the Corporation and the Employee.

         12. Governing Law. This Agreement shall be construed, interpreted and
enforced in accordance with the laws of the State of New Hampshire.

         13. Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the parties and their respective successors and assigns,
including any corporation with which or into which the Bank or the Corporation
may be merged or which may succeed to its assets or business, provided, however,
that the obligations of the employee are personal and shall not be assigned by
him.

         14. Miscellaneous.

                  14.1 No delay or omission by the Bank or the Corporation in
exercising any right under this Agreement shall operate as a waiver of that or
any other right. A waiver or consent given by the Bank or the Corporation on any
one occasion shall be effective only in that instance and shall not be construed
as a bar or waiver of any right on any other occasion.


                                        7
<PAGE>   8
                  14.2 The captions of the sections of this Agreement are for
convenience of reference only and in no way define, limit or affect the scope or
substance of any section of this Agreement.

                  14.3 In case any provision of this Agreement shall be invalid,
illegal or otherwise unenforceable, the validity, legality and enforceability of
the remaining provisions shall in no way be affected or impaired thereby.

                  14.4 All obligations of the Bank or the Corporation hereunder
shall be joint and several obligations of both the Bank and the Corporation.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year set forth above.

                                        PORTSMOUTH SAVINGS BANK


                                        By:/s/Mark E. Simpson
                                           ------------------------------
                                           Mark E. Simpson
                                           President and
                                           Chief Operating Officer


                                        PORTSMOUTH BANK SHARES, INC.


                                        By:/s/Harry R. Hart
                                           ------------------------------
                                           Harry R. Hart
                                           President and
                                           Chief Executive Officer


                                        EMPLOYEE


                                        /s/John J. Pratt, Jr.
                                        ---------------------------------
                                        John J. Pratt, Jr.


                                        8