Exhibit 10.2.3

INVESTMENT MANAGEMENT AGREEMENT

WHITE MOUNTAINS ADVISORS LLC, a Delaware limited liability company (the
“Advisor”), having an address at 370 Church Street, Guilford, Connecticut 06437,
and                                                                           ,
a                       corporation (the “Client”), having an address at One
Beacon Street, Boston, Massachusetts 02108, hereby enter into this Investment
Management Agreement, dated as of November 14, 2006 (this “Agreement”), and
hereby agree that the Advisor shall act as discretionary adviser with respect to
the assets of the Client described below (the “Investment Account”) on the
following terms and conditions:

1.                                       Investment Account.  The Investment
Account shall consist of cash and the securities of the Client.

2.                                       Services of Advisor.  By execution of
this Agreement, the Advisor accepts appointment as adviser for the Investment
Account with full discretion and agrees to supervise and direct the investments
of the Investment Account in accordance with the investment objectives, policies
and restrictions described in the investment guidelines to be furnished by the
Client to the Advisor from time to time (the “Investment Guidelines”).  The
Investment Guidelines are for the stated purpose of assisting the Advisor in the
performance of its investment duties.  The Advisor will manage the Investment
Account in accordance with such Investment Guidelines as provided to the Advisor
from time to time.  In addition, the Advisor agrees to provide treasury
management advisory services specific to the Investment Account (“Treasury
Management Services”), as directed by the Client.  The Treasury Management
Services include, without limitation, (i) executing investment transactions to
support short-term treasury cash requirements, (ii) settling inter-company and
dividend treasury transactions with cash and securities, (iii) settling
quarterly tax liability payments from the Investment Account, (iv) providing
preliminary valuation for securities supporting treasury transactions, (v)
assisting the Client in evaluating securities lending programs administered by
custodians designated by the Client and acceptable to the Advisor, and (vi)
collaborating with the Client to provide treasury transaction support to
custodians and accounting servicing providers designated by the Client and
acceptable to the Advisor.

3.                                       Discretionary Authority.  Advisor shall
have full discretion and authority, without obtaining any prior approval, as the
Client’s agent and attorney-in-fact: (a) to make all investment decisions in
respect of the Investment Account on the Client’s behalf and at the Client’s
sole risk; (b) to buy, sell, exchange, convert, liquidate or otherwise trade in
any stock, bond and other securities in respect of the Investment Account;
(c) to place orders with respect to, and to arrange for, any of the foregoing;
and (d) in furtherance of the foregoing, to do anything which the Advisor shall
deem requisite, appropriate or advisable in connection therewith, including,
without limitation, the selection of such brokers, dealers, and others as the
Advisor shall determine in its absolute discretion. 

4.                                       Liability.  In the performance of its
services, the Advisor will not be liable for any error in judgment or any acts
or failures to act except those resulting from the Advisor’s gross negligence,
willful misconduct or malfeasance.  Nothing herein shall in any way constitute a
waiver or limitation of any right of any person under the federal securities
laws.  The Advisor shall have no

1

--------------------------------------------------------------------------------

responsibility whatsoever for the management of any assets of the Client other
than the Investment Account.

5.                                       Custody.  The assets of the Investment
Account shall be held in one or more separately identified accounts in the
custody of one or more banks, trust companies, brokerage firms or other entities
designated by the Client and acceptable to the Advisor.  The Advisor will
communicate its investment purchase, sale and delivery instructions directly
with the Client’s custodian or other qualified depository.  The Client shall be
responsible for all custodial arrangements and the payment of all custodial
charges and fees, and the Advisor shall have no responsibility or liability with
respect to custody arrangements or the acts, omissions or other conduct of the
custodians.

6.                                       Brokerage.  When placing orders for the
execution of transactions for the Investment Account, the Advisor may allocate
all transactions to such brokers or dealers, for execution on such markets, at
such prices and commission rates, as are selected by the Advisor in its sole
discretion.  In selecting brokers or dealers to execute transactions, the
Advisor need not solicit competitive bids and does not have an obligation to
seek the lowest available commission cost.  It is not the Advisor’s practice to
negotiate “execution only” commission rates, and, in negotiating commission
rates, the Advisor shall take into account the financial stability and
reputation of brokerage firms and brokerage and research services provided by
such brokers.  The Client may be deemed to be paying for research provided or
paid for by the broker which is included in the commission rate although the
Client may not, in any particular instance, be the direct or indirect
beneficiary of the research services provided.  Research furnished by brokers
may include, but is not limited to, written information and analyses concerning
specific securities, companies or sectors; market, finance and economic studies
and forecasts; financial publications; statistics and pricing services;
discussions with research personnel; and software and data bases utilized in the
investment management process.  The Client acknowledges that since commission
rates are generally negotiable, selecting brokers on the basis of considerations
which are not limited to applicable commission rates may at times result in
higher transaction costs than would otherwise be obtainable.  The Advisor is
hereby authorized to, and the Client acknowledges that the Advisor may,
aggregate orders on behalf of the Investment Account with orders on behalf of
other clients of the Advisor.  In such event, allocation of the securities
purchased or sold, as well as expenses incurred in the transaction, shall be
made in a manner which the Advisor considers to be the most fair and equitable
to all of its clients, including the Client.

                                               
7.                                       Representations and Warranties.

(a)          The Client represents, warrants, covenants and agrees that:

(i)                             it has full legal power and authority to enter
into this Agreement;

(ii)                          the appointment of the Advisor hereunder is
permitted by the Client’s governing documents and has been duly authorized by
all necessary corporate or other action, and

(iii)                       it will indemnify the Advisor and hold it harmless
against any and all  losses, costs, claims and liabilities which the Advisor may
suffer or

2

--------------------------------------------------------------------------------

incur arising out of any material breach of these representations and warranties
of the Client.

(b)         The Advisor represents, warrants, covenants and agrees that:

(i)                             it has full legal power and authority to enter
into this Agreement;

(ii)                          it is registered as an investment adviser with the
Securities and Exchange Commission pursuant to the Investment Advisers Act of
1940, as amended (the “Advisers Act”);

(iii)                       entering into this Agreement has been duly
authorized by all necessary corporate or other action under the Advisor’s
governing document, and

(iv)                      it will indemnify the Client and hold it harmless
against any and all losses, costs, claims and liabilities which the Client may
suffer or incur arising out of any material breach of any representations and
warranties of the Advisor.

8.                                       Reports.  The Advisor shall provide the
Client with reports containing the status of the Investment Account at least
monthly, and will provide written advisory report letters to the Client on a
quarterly basis.  The Advisor shall also provide the Client with preliminary
valuation of the Investment Account on a monthly basis.  The preliminary
valuation will be determined in accordance with the Advisor’s valuation policies
and procedures, a copy of which shall be provided to the Client at least
annually.  All records maintained pursuant to this Agreement shall be subject to
examination by the Client and by persons authorized by it, or by appropriate
governmental authorities, at all times upon reasonable notice.  The Advisor
shall provide copies of trade tickets, custodial reports and other records the
Client reasonably requires for accounting or tax purposes.

9.                                       Management Fee, Treasury Management Fee
and Expenses.

(a)   The Advisor will be paid a quarterly management and treasury management
fee (the “Management Fee”) for its investment advisory and treasury management
services provided hereunder, determined in accordance with Schedule A to this
Agreement.  During the term of this Agreement, the Management Fee shall be
billed and payable in arrears on a quarterly basis within 10 days after the last
day of each calendar quarter based upon the value of the Investment Account as
of the last day of the immediately preceding calendar quarter.  The Management
Fee shall be pro-rated for any partial quarter.  Capital inflows and outflows
result in an adjustment to the value of assets under management that serves as
the base of the Management Fee.  This adjustment has the effect of
time-weighting capital flows in the account resulting in the Management Fee
being properly charged for only the period of time such assets are actually
managed by the Advisor.  It is understood that, in the event that the Management
Fee is to be paid by the custodian out of the Investment Account, the Client
will provide written authorization to the custodian to pay the Management Fee
directly from the Investment Account.

(b)   The Client shall be responsible for all expenses incurred directly in
connection with transactions effected on behalf of the Client pursuant to this
Agreement and shall include:  custodial fees; PAM accounting service fees,
Charles River compliance service fees, investment expenses such as commissions;
and other expenses reasonably related to the purchase, sale or

3

--------------------------------------------------------------------------------

transmittal of Investment Account assets (other than research fees and expenses
with respect to the Investment Account).

10.                                 Confidential Relationship.  All information
and advice furnished by either party to the other party pursuant to this
Agreement shall be treated by the receiving party as confidential and shall not
be disclosed to third parties except as required by law.

11.                                 Assignment.  This agreement may not be
assigned (within the meaning of the Advisers Act) by either party without the
written consent of the other party, and any assignment without such consent
shall automatically cause the termination hereof.

12.                                 Directions to the Advisor.  All directions
by or on behalf of the Client to the Advisor shall be in writing signed by or on
behalf of the Client.  The Advisor shall be fully protected in relying upon any
such writing which the Advisor believes to be genuine and signed or presented by
the proper person or persons, shall be under no duty to make any investigation
or inquiry as to any statement contained therein and may accept the same as
conclusive evidence of the truth and accuracy of the statements therein
contained.

13.                                 Services to Other Clients.  It is understood
that the Advisor acts as investment adviser to other clients and may give advice
and take action with respect to such clients that differs from the advice given
or the action taken with respect to the Investment Account.  Nothing in this
Agreement shall restrict the right of the Advisor, its members, managers,
officers, employees or affiliates to perform investment management or advisory
services for any other person or entity, and the performance of such service for
others shall not be deemed to violate or give rise to any duty or obligation to
the Client.

14.                                 Investment by the Advisor for Its Own
Account.  Nothing in this Agreement shall limit or restrict the Advisor or any
of its members, managers, officers, employees or affiliates from buying, selling
or trading any securities for its or their own account or accounts.  The Client
acknowledges that the Advisor and its members, managers, officers, employees,
affiliates and other clients may at any time have, acquire, increase, decrease
or dispose of securities which are at or about the same time acquired or
disposed of for the account of the Client.  The Advisor shall have no obligation
to purchase or sell for the Investment Account or to recommend for purchase or
sale by the Investment Account any security that the Advisor or its members,
managers, officers, employees or affiliates may purchase or sell for itself or
themselves or for any other client.

15.                                 Proxies.  Subject to any other written
instructions of the Client, the Advisor is hereby appointed as the Client’s
agent and attorney-in-fact in its discretion to vote, convert or tender in an
exchange or tender offer any securities in the Investment Account, to execute
proxies, waivers, consents and other instruments with respect to such
securities, to endorse, transfer or deliver such securities and to participate
in or consent to any plan of reorganization, merger, combination, consolidation,
liquidation or similar plan with reference to such securities, and the Advisor
shall not incur any liability to the Client by reason of any exercise of, or
failure to exercise, any such discretion.

16.                                 Notices.  All notices and instructions with
respect to securities transactions or any other matters contemplated by this
Agreement shall be deemed duly given when delivered in writing, via electronic
communications or deposited by first-class mail to the following addresses:

4

--------------------------------------------------------------------------------

(a) if to the Advisor, at its address set forth above, Attention: Chief
Financial Officer, or (b) if to the Client, at its address set forth above,
Attention: Chief Financial Officer.  The Advisor or the Client may change its
address or specify a different manner of addressing itself by giving notice of
such change in writing to the other party.

17.                                 Entire Agreement; Amendment.  This Agreement
sets forth the entire agreement of the parties with respect to management of the
Investment Account, supersedes any previous Investment Management Agreement
between the Advisor and the Client and shall not be amended except by an
instrument in writing signed by the parties hereto.

18.                                 Arbitration.  Any controversy or claim
arising out of or relating to this Agreement, or the breach of the same, shall
be settled by arbitration in accordance with the rules of the American
Arbitration Association, and judgment upon the award rendered by the arbitrators
may be entered in any court having jurisdiction.  All arbitration expenses shall
be borne equally by the Advisor and the Client.

19.                                 Termination.  This Agreement shall continue
in force in accordance with paragraph 21, Effective Date and Term of this
Agreement.  During such term, this Agreement may be terminated by the Client
upon written notice to the Advisor at least sixty (60) days prior to the date
upon which such termination is to become effective only (i) for cause (including
material non-performance by the Advisor), (ii) if there is a change in control
of the Advisor (for this purpose, a change in control represents 50% or more of
voting interest of the Advisor) or (iii) if White Mountains Insurance Group,
Ltd.’s voting interest in Client falls below 50%.  Following the end of the
initial fixed term and any extensions, as provided by paragraph 21, Effective
Date and Term of this Agreement, the Agreement may be terminated by either party
without penalty by written notice to the other party at least sixty (60) days
prior to the date upon which such termination is to become effective, provided
that the Client shall honor any trades executed but not settled before the date
of any such termination.  Upon termination of this Agreement, any accrued and
unpaid Management Fee and Treasury Management Fee hereunder shall be paid by the
Client to the Advisor.

20.                                 Governing Law.  To the extent that the
interpretation or effect of this Agreement shall depend on state law, this
Agreement shall be governed by and construed in accordance with the laws of the
State of New York.

21.                                 Effective Date and Term.  This Agreement
shall become effective on the first date written above for an initial fixed term
of three years, which will be extendible by the Client for an additional one
year (a fourth year) at/prior to the end of the second year of the term, and if
so extended, for a second additional year (a fifth year) at/prior to the end of
the third year of the term.

22.                                 Receipt of Disclosure Statement.  The Client
acknowledges receipt of a copy of Part II of the Advisor’s Form ADV in
compliance with Rule 204-3(b) under the Investment Advisers Act of 1940, as
amended, more than 48 hours prior to the date of execution of this Agreement. 
The Advisor shall annually and without charge, upon request by the Client,
deliver to the Client the current version of such form or a written document
containing at least the information then required to be contained in such form.

5

--------------------------------------------------------------------------------

23.                                 Counterparts.  This Agreement may be
executed in two counterparts, each one of which shall be deemed to be an
original.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
by their respective duly authorized representatives as of the date first written
above.

ADVISOR:

 

CLIENT:

 

 

 

 

 

 

 

 

 

WHITE MOUNTAINS ADVISORS, LLC

 

[see client schedule]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

By:

/s/ Mark K. Dorcus

 

By:

/s/ Frederick J. Turcotte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Print:

Mark K. Dorcus

 

Print:

Frederick J. Turcotte

 

 

 

 

 

 

 

 

 

Title:

President and Managing Director

 

Title:

Vice President, Investor Relations, Treasurer

 

 

 

 

and Tax Director

6

--------------------------------------------------------------------------------

SCHEDULE A

FEE SCHEDULE

1.                                       Investment Account.

Assets Under Management

 

Value

 

Annual Fee

 

Quarterly Fee

 

Investment Grade Fixed Income:

 

 

 

 

 

 

 

— Up to $999 million

 

Market

 

10.0 basis points (0.1% or 0.001)

 

2.5 basis points (0.025% or 0.00025)

 

— Next $1 - $1.999 billion

 

Market

 

8.5 basis points

 

2.125 basis points

 

— Amounts over $2 billion

 

Market

 

7.5 basis points

 

1.875 basis points

 

High Yield Debt

 

Market

 

25.0 basis points

 

6.25 basis points

 

Fully Funded Hedge Funds, Limited Partnerships and Limited Liability Companies

 

Market

 

100.0 basis points

 

25.0 basis points

 

Private Equities and Other Deferred Fundings:

 

 

 

 

 

 

 

— First 2 Years of Fund’s Life

 

Committed

 

100.0 basis points

 

25.0 basis points

 

— Thereafter

 

Market

 

100.0 basis points

 

25.0 basis points

 

 

For purposes of calculating the fee for Investment Grade Fixed Income
investments as provided above, the assets under management of OneBeacon
Insurance Group, Ltd. and all of its direct and indirect subsidiaries will be
aggregated.

2.                     Treasury Management Services.  The Advisor will be paid a
quarterly fee for the Treasury Management Services computed at the annual rate
of 1.75 basis points (0.0175%) of the aggregate value of the net assets of the
Client’s Investment Account on an annual basis utilizing the methodologies
described in Paragraph 1 of Exhibit A.  In the first year of the Agreement, the
Treasury Management Services fee shall not exceed $500,000 on an annual basis.

7

--------------------------------------------------------------------------------

 

Client Schedule:

 

 

Pennsylvania General Insurance Company

 

OneBeacon Insurance Group, Ltd.

 

Potomac Insurance Company

 

8

--------------------------------------------------------------------------------