EXHIBIT 99.2

[LOGO] TRENWICK GROUP LTD.

STOCK OPTION EXCHANGE PROGRAM

TENDER OFFER STATEMENT

("OFFER TO EXCHANGE")

----------------------------------------------
The Offer and Withdrawal Rights
Expire at 11:59 P.M., Eastern Time (U.S.),
On June 14, 2002 (The "Expiration Date"),
Unless the Offer is Extended by Trenwick Group Ltd.
----------------------------------------------

May 16, 2002

Any questions or requests for assistance or additional copies of any documents
referred to in the Offer to Exchange may be directed to:

Trenwick Group Ltd.
c/o Trenwick Services Inc.
One Canterbury Green
Stamford, CT 06901
Telephone: 203-353-5500

May 16, 2002

Trenwick Group Ltd., which we refer to as "we," or "Trenwick," is offering
Eligible Employees (as defined below) the opportunity to exchange all, but not
less than all, of their outstanding stock options to purchase Trenwick common
shares for New Options which will be granted under our Option Plans.

The following is a summary of the material terms of the Offer. We urge you
to read carefully the remainder of this document. We have included references to
the relevant sections in this document where you can find a more complete
description of the topics in this summary.

o Offer. We are making this Offer upon the terms and subject to the
conditions described in (i) this Stock Option Exchange Program Tender
Offer Statement (the "Offer to Exchange"); and (ii) the related election
package (which together, as they may be amended from time to time,
constitute the "Offer"). This Offer is not conditioned upon a minimum
number of Current Options (as defined below) being exchanged. This Offer
is subject to the conditions that we describe in "Summary of Terms"
question 6 and "The Offer: 7. Conditions of the Offer."

o Voluntary. Participation in the Offer is voluntary.

o Current Options. We are offering our eligible employees, excluding our
Chairman, President and Chief Executive Officer and members of our Board
of Directors, the opportunity to exchange all of their outstanding options
(the "Current Options") for new options to purchase our common shares. See
"Summary of Terms" questions 3, 4 and 5 and "The Offer: 2. Number of
Options; Expiration Date."

o Option Plans. The Current Options have been granted under one of the
following of our stock option plans: the Trenwick Group Inc. 1989 Stock
Plan, the Trenwick Group Inc. 1993 Stock Option Plan, the Chartwell Re
Corporation 1993 Stock Option Plan, the Chartwell Re Corporation 1997
Omnibus Stock Incentive Plan and the LaSalle Re Holdings Limited 1996
Long-Term Incentive Plan (together, the "Option Plans" and individually,
an "Option Plan"). See "Summary of Terms" question 3 and "The Offer: 2.
Number of Options; Expiration Date."

o New Options. The new options to purchase our common shares that are
granted in exchange for an Eligible Employee's Current Options (the "New
Options") will be granted under the same Option Plan as the Current Option
they replace.

o Expiration Date. To participate in the Offer, an Eligible Employee must
properly tender all of his or her Current Options prior to 11:59 P.M.,
Eastern Time (U.S.), on June 14, 2002, unless we extend the period of time
the Offer is open (the "Expiration Date").

o Cancellation Date. If an Eligible Employee accepts this Offer and tenders
his or her Current Options for exchange, all of the Eligible Employee's
Current Options will be cancelled on the first day following the
Expiration Date (the "Cancellation Date"). The Offer is presently
scheduled to expire on June 14, 2002 and we expect the Cancellation Date
to be June 15, 2002. If Current Options are not accepted in the Offer by
July 12, 2002, you may withdraw your tender.

o All or Nothing. To participate in the Offer, an Eligible Employee must
tender all of his or her Current Options for cancellation. In other words,
an Eligible Employee may not tender some of his or her Current Options and
keep the balance of his or her Current Options. If an Eligible Employee
wishes to tender any of his or her Current Options, the Eligible Employee
must tender all of his or her Current Options.

o Grant Date of New Options. The New Options will be granted on a date which
is at least six months and one day after the Cancellation Date (the "Grant
Date"). Assuming we do not extend the Expiration Date, we presently expect
the Grant Date to be no earlier than December 16, 2002. If the Expiration
Date of the Offer is extended by us, the Grant Date for the New Options
will also be extended.

o Exchange Ratios. Each Eligible Employee who accepts the Offer will receive
in exchange for his or her Current Options that are accepted for exchange
and cancelled, that number of New Options determined based on the grant
price of the Current Option as follows:

Grant Price of Current Option Exchange Ratios
----------------------------- ---------------
Less than $15.00 1.5 for 1
$15.00 through $20.99 2 for 1
$21.00 through $26.99 2.5 for 1
$27.00 and higher 3 for 1

We will not issue any New Options exercisable for fractional shares.
Instead, we will round up (.50 or over) or down (.49 or under) to the
nearest whole number of shares with respect to each option. The New
Options shall be subject to adjustments for any future share splits, share
dividends and similar events, in accordance with the terms of the
applicable Option Plan. See "Summary of Terms" questions 15 and 16 and
"The Offer: 2. Number of Options; Expiration Date."

o Eligible Employees. All employees of Trenwick, other than its Chairman,
President and Chief Executive Officer, are eligible to participate in this
Offer if they: (i) are employed by Trenwick or a Participating Subsidiary
(as defined below) on the date the Offer commences; (ii) hold Current
Options on the date the Offer commences; (iii) remain an employee of
Trenwick or one of its Participating Subsidiaries through the Expiration
Date; and (iv) do not, on or prior to the Expiration Date, elect to
terminate their employment or receive a notice of termination from their
employer (individually an "Eligible Employee"). See "Summary of Terms"
question 4 and "The Offer: 1. Eligible Employees" and "The Offer: 9.
Source and Amount of Consideration; Terms of New Options."

o Termination of Employment. To receive New Options, an Eligible Employee
must remain employed through the Grant Date. Eligible Employees who
terminate employment for any reason, whether voluntary or involuntary,
after the Expiration Date and prior to the Grant Date will not receive a
grant of New Options or any other consideration or payment for the
cancellation of their Current Options. See "Summary of Terms" questions 7,
8, 9, 10, 11, 30 and 31, "Certain Risks of Participating in the Offer" and
"The Offer: 1. Eligible Employees" and "The Offer: 9. Source and Amount of
Consideration; Terms of New Options."

o Grant Price. The grant price of the New Options will be the closing sale
price of our common shares on the New York Stock Exchange on the Grant
Date. See "Summary of Terms" question 20 and "The Offer: 9. Source and
Amount of Consideration; Terms of New Options."

o Vesting. The New Options will vest two years from the Grant Date. See
"Summary of Terms" question 21 and "The Offer: 9. Source and Amount of
Consideration; Terms of New Options."

o Options Not Eligible to Participate in the Offer. The Offer will have no
effect on those options that are not eligible to participate in this
Offer. Those options will remain outstanding in accordance with and
subject to their terms. See "Summary of Terms" question 17 and "The Offer:
9. Source and Amount of Consideration; Terms of New Options."

o Effect on Current Options Which Are Not Tendered. If you chose not to
tender your Current Options for exchange or if we do not accept tendered
options for exchange or, if having tendered, you withdraw prior to the
Expiration Date, your Current Options will remain outstanding and retain
their current exercise prices and other current terms. We currently expect
that we will accept all properly tendered Current Options promptly after
the expiration of this Offer. See "The Offer: 6. Acceptance of Current
Options for Exchange and Issuance of New Options."

o Exercise Period. Each New Option will have a term of five years. See
"Summary of Terms" question 23, and "The Offer: 9. Source and Amount of
Consideration; Terms of New Options."

o Participating Subsidiary. Any entity in which Trenwick directly or
indirectly has an ownership interest of more than 50% will be a
"Participating Subsidiary."

o No Recommendation. Although our Board of Directors has approved the making
of this Offer, neither we nor our Board of Directors makes any
recommendation as to whether an Eligible Employee should tender or refrain
from tendering his or her Current Options. An Eligible Employee must make
his or her own decision whether to tender his or her Current Options. See
"Summary of Terms" question 40 and "The Offer: 3. Purpose of the Offer."

o Recent Trading Price. Our common shares are listed for trading on the New
York Stock Exchange under the symbol "TWK." On May 14, 2002, the closing
sale price of our common shares on the New York Stock Exchange was $8.35
per share. We recommend that you obtain current market quotations for our
common shares before deciding whether to tender your Current Options. See
"The Offer: 8. Price Range of Common Shares Underlying the Current
Options."

o How To Obtain More Information. Questions about this Offer or requests for
additional copies of this Offer to Exchange or the Election Package should
be directed to Trenwick Group Ltd., c/o Trenwick Services Inc.,
203-353-5500. For more information about Trenwick, see "The Offer: 10.
Information Concerning Trenwick" and "The Offer: 18. Additional
Information."

This transaction has not been approved or disapproved by the
Securities and Exchange Commission or any state securities commission nor has
the Securities and Exchange Commission or any state securities commission passed
upon the fairness or merits of this transaction or upon the accuracy or adequacy
of the information contained in this Offer. Any representation to the contrary
is a criminal offense.

IMPORTANT

If you wish to tender your Current Options for exchange, you must,
prior to 11:59 P.M., Eastern Time (U.S.), on June 14, 2002, unless the Offer is
extended, deliver a properly completed, signed and dated Election Form by mail
to Trenwick Group Ltd., c/o Trenwick Services Inc., One Canterbury Green,
Stamford, CT 06901, U.S.A, Attn: Legal Department or by facsimile to
203-353-5550.

The grant price of the New Options will be the closing sale price of
our common shares on the New York Stock Exchange on the Grant Date. We cannot
guarantee that the New Options will have a lower grant price than the Current
Options.

The decision to accept the Offer is an individual one that should be
based on a variety of factors, and you should consult your own personal advisors
if you have any questions about your financial or tax situation. The information
about this Offer is limited to: (i) this Offer to Exchange; and (ii) the
Election Package.

We have not authorized any person to make any recommendation on our
behalf as to whether or not you should tender your Current Options pursuant to
the Offer. We have not authorized anyone to give you any information or to make
any representation in connection with this Offer other than the information and
representations contained in the Offer. If anyone makes any recommendation or
representation to you or gives you any information, you must not rely upon that
recommendation, representation or information as having been authorized by us.

TABLE OF CONTENTS

Page

SUMMARY OF TERMS..............................................................4
CERTAIN RISKS OF PARTICIPATING IN THE OFFER..................................14
THE OFFER....................................................................16
1. Eligible Employees....................................................16
2. Number of Options; Expiration Date....................................17
3. Purpose of the Offer..................................................18
4. Procedures for Participating in the Offer to Exchange.................19
5. Withdrawal Rights.....................................................19
6. Acceptance of Current Options for Exchange and Issuance
of New Options........................................................20
7. Conditions of the Offer...............................................21
8. Price Range of Common Shares Underlying the Current Options...........23
9. Source and Amount of Consideration; Terms of New Options..............24
10. Information Concerning Trenwick.......................................28
11. Interests of Directors and Executive Officers; Transactions and
Arrangements Concerning Current Options and Our Common Shares.........28
12. Status of Current Options Acquired by Us in the Offer; Accounting
Consequences of the Offer.............................................29
13. Legal Matters; Regulatory Approvals...................................29
14. Material U.S. Federal Income Tax Consequences.........................30
15. Material Tax Consequences for Employees Who Are Tax
Residents in the United Kingdom.......................................30
16. Extension of Offer; Termination; Amendment............................31
17. Fees and Expenses.....................................................32
18. Additional Information................................................32
19. Summary Financial Information.........................................33
20. Forward Looking Statements............................................33
21. Miscellaneous.........................................................34
SCHEDULE A - Information Concerning the Directors and Executive Officers
of Trenwick...........................................................35

SUMMARY OF TERMS

The following are answers to some of the questions that you may have
about this Offer. We urge you to also read carefully the remainder of this Offer
because it contains additional important information. In addition, we urge you
to review the information in our annual report on Form 10-K for the year ended
December 31, 2001, quarterly report on Form 10-Q for the quarter ended March 31,
2002, and the proxy statement distributed in connection with our Annual General
Meeting of Shareholders held on May 15, 2002, as these documents contain
important financial and other relevant information about us. All of these
documents may be obtained without charge from us or from the Securities and
Exchange Commission. See "The Offer: 18. Additional Information."

INDEX TO SUMMARY OF TERMS

Question Page
- -------- ----
1. What is the Stock Option Exchange Program?.............................7
2. Why are we making the Offer?...........................................7
3. What securities are we offering to Exchange?...........................7
4. Who is eligible to participate in the Offer?...........................7
5. Are employees located outside the United States eligible to
participate in the Offer?..............................................7
6. What are the conditions to the Offer?..................................7
7. What if I leave or am terminated prior to the expiration
of the Offer?..........................................................8
8. What if I elect to leave or receive a notice of termination
prior to the expiration of the Offer?..................................8
9. Must I remain an employee in order to receive the
New Options?...........................................................8
10. What if I tender my Current Options, but am not an employee
of Trenwick or one of its Participating Subsidiaries when the
New Options are granted?...............................................8
11. What if I tender my Current Options, but die after
the Expiration Date and prior to the Grant Date?.......................8
12. If I choose to tender my Current Options for exchange,
do I have to tender all of my Current Options?.........................8
13. May I tender options I have already exercised?.........................9
14. Will I be required to give up all my rights to the cancelled
options?...............................................................9
15. How can I find out the details of my options that are eligible for
this Offer?............................................................9
16. How many New Options will I receive in exchange for my tendered
options?...............................................................9
17. What happens if I do not accept the Offer?............................10
18. When will I receive my New Options?...................................10
19. Why won't I receive my New Options immediately after the
Expiration Date of the Offer?.........................................10
20. What will be the grant price of the New Options?......................10
21. When will the New Options vest?.......................................10
22. What if my employment terminates before the New Options vest? ........10
23. When will the New Option expire?......................................10
24. Will the terms and conditions of my New Options be the
same as the terms and conditions of my Current Options?...............10
25. Why don't we simply change the grant price of the Current Options?....11
26. Why can't I just be granted more options without having my Current
Options cancelled?....................................................11
27. Will I have to pay taxes if I exchange my Current Options in the
Offer?................................................................11
28. Will Trenwick grant options to employees during the period
beginning on the date this Offer commences, and ending on the date
tendered Current Options are cancelled?...............................11
29. Will I be considered for additional option grants before the Grant
Date of the New Options?..............................................11
30. What happens if I tender my Current Options and I am on a leave of
absence on the New Option Grant Date?.................................11
31. What types of leave of absence are considered "authorized leaves
of absences?".........................................................12
32. After the grant of my New Options, what happens if the market
price of Trenwick's common shares goes below the grant price for
those New Options?....................................................12
33. What happens if Trenwick merges into or is acquired by another
company?..............................................................12
34. When does the Offer expire? Can the Offer be extended, and if so,
how will I be notified if it is extended?.............................12
35. Do I have to participate in the Offer?................................13
36. What happens to my Current Options if I decide not to participate
in the Offer?.........................................................13
37. What do I need to do to participate in the Offer?.....................13
38. Can I change my election?.............................................13
39. If I choose not to participate in the Offer, what do I have to do?....14

Question Page
- -------- ----
40. What will happen if I do not elect to participate in the Offer
by the end of the tender offer period?................................14
41. What does Trenwick and its Board of Directors think of this Offer?....14
42. How should I decide whether or not to participate?....................14
43. Who can I talk to if I have questions about the Offer?................14
44. Does this Offer cover stock appreciation rights?......................14

1. What is the Stock Option Exchange Program?

Our Stock Option Exchange Program is a voluntary program that offers
Eligible Employees the opportunity to make a one-time election to cancel all of
their Current Options and exchange them for New Options. This Offer will remain
open until 11:59 P.M., Eastern Time (U.S.), on June 14, 2002, unless the Offer
is extended (the "Expiration Date"). If you accept this Offer, your Current
Options tendered for exchange will be cancelled on the first day following the
Expiration Date (the "Cancellation Date"). The New Options will be granted on a
date which is at least six months and one day after the Cancellation Date (the
"Grant Date"). Assuming we do not extend the Expiration Date, we presently
expect the Grant Date to be no earlier than December 16, 2002.

2. Why are we making the Offer?

Virtually all of your outstanding stock options, whether or not they are
currently vested and exercisable, have grant prices that are significantly
higher than the current market price of our common shares. For our stock option
programs to provide the intended motivation and retention to you, you must feel
that our stock options provide you with an opportunity to realize value within a
reasonable period of time. With the uncertainty of current market conditions, we
believe that you may feel that the opportunity for realizing value is limited
with your Current Options. By making this Offer, we intend to provide you with
the benefit of holding options that over time may have a greater potential to
increase in value, and thereby create an incentive for you to remain with us and
contribute to the attainment of our business and financial objectives and the
creation of value for our shareholders.

3. What securities are we offering to exchange?

We are offering to exchange all outstanding, unexercised stock options to
purchase our common shares granted under the Trenwick Group Inc. 1989 Stock
Plan, the Trenwick Group Inc. 1993 Stock Option Plan, the Chartwell Re
Corporation 1993 Stock Option Plan, the Chartwell Re Corporation 1997 Omnibus
Stock Incentive Plan and the LaSalle Re Holdings Limited 1996 Long-Term
Incentive Plan (together, the "Option Plans" and individually, an "Option Plan")
that are held by Eligible Employees (the "Current Options") in return for new
options that we will grant under the same Option Plan pursuant to which the
cancelled Current Option it replaces was granted (the "New Options").
Outstanding stock appreciation rights issued under an Option Plan are not
eligible for the Stock Option Exchange Program.

4. Who is eligible to participate in the Offer?

All employees of Trenwick or any its Participating Subsidiaries, other
than the Chairman, President and Chief Executive Officer and members of the
Board of Directors of Trenwick, are eligible to participate in this Offer if
they: (i) are employed by Trenwick or a Participating Subsidiary on the date the
Offer commences; (ii) hold Current Options on the date the Offer commences;
(iii) remain an employee of Trenwick or one of its Participating Subsidiaries
through the Expiration Date; and (iv) do not, on or prior to the Expiration
Date, elect to terminate their employment or receive a notice of termination
from their employer (individually, an "Eligible Employee").

5. Are employees located outside the United States eligible to participate in
the Offer?

All Eligible Employees, including Eligible Employees located outside the
United States, may participate in the Offer. Special considerations may apply to
Eligible Employees located outside the United States. In some countries, the
application of local rules may have important consequences to those Eligible
Employees. If you are an Eligible Employee located outside the United States,
you should review these summaries and consult your individual tax, legal and
investment advisors.

6. What are the conditions to the Offer?

The Offer is not conditioned on a minimum number of Current Options being
tendered. Participation in the Offer is voluntary. The Offer is subject to a
number of conditions with regard to events that could occur prior to the
expiration of the Offer. These events include, among other things, a change in
accounting principles, a lawsuit challenging the Offer, a third-party tender
offer for our common shares or other acquisition proposal, or a change in your
employment status with us. These and various other conditions are more fully
described in "The Offer: 7.

Conditions of the Offer" below. Once the Offer has expired and the tendered
Current Options have been accepted and cancelled, the conditions will no longer
apply, even if the specified events occur during the period between the
Expiration Date and the date of grant of the New Options. However, as described
below, a change in your employment status during that period could result in you
not receiving a grant of New Options.

7. What if I leave or am terminated prior to the expiration of the Offer?

If you are not employed by Trenwick or a Participating Subsidiary on the
date of the expiration of the Offer, you will not be an Eligible Employee and,
as a result, you will not be eligible to participate in the Offer. If you tender
your Current Options prior to your termination of employment, your tender will
be automatically withdrawn. You may exercise your Current Options in accordance
with their terms to the extent they are vested. Since your tendered Current
Options will automatically be withdrawn, you will not receive any New Options in
exchange for your Current Options.

If you are employed on at "at-will" basis, this Offer does not change the
"at-will" nature of your employment, and, therefore, your employment may be
terminated by your employer or by you at any time, including prior to the Grant
Date of the New Options, for any reason, with or without cause.

8. What if I elect to leave or receive a notice of termination prior to the
expiration of the Offer?

If prior to the date of the expiration of the Offer, you either elect to
leave Trenwick or a Participating Subsidiary or receive a notice of termination
from your employer, you will not be an Eligible Employee and, as a result, you
will not be eligible to participate in the Offer. If you tender your Current
Options prior to electing to leave or receiving a notice of termination of
employment, your tender will automatically be withdrawn. You may exercise your
Current Options in accordance with their terms to the extent they are vested.
Since your tendered Current Options will automatically be withdrawn, you will
not receive any New Options in exchange for your Current Options.

9. Must I remain an employee in order to receive the New Options?

Yes. To receive the New Options, you must remain an employee of Trenwick
or a Participating Subsidiary through the date we grant the New Options. The New
Options will be granted at least six months and one day after the date the
tendered Current Options are accepted for exchange and cancelled (the "Grant
Date"). Assuming we do not extend the Expiration Date, we presently expect the
Grant Date to be no earlier than December 16, 2002.

10. What if I tender my Current Options, but am not an employee of Trenwick or
one of its Participating Subsidiaries when the New Options are granted?

If you do not remain an employee of Trenwick or one of its Participating
Subsidiaries from the date you tender your Current Options through the date your
New Options are granted, you will not receive any New Options or any other
payment or consideration in exchange for your tendered Current Options that have
been accepted for exchange and cancelled. This rule applies regardless of the
reason of your termination of employment and whether a result of voluntary
resignation, involuntary termination, death or disability.

11. What if I tender my Current Options, but die after the Expiration Date and
prior to the Grant Date?

Once your Current Options are cancelled, should you die, prior to the
Grant Date of the New Options, neither you nor your estate or heirs will receive
any New Options or any other payment or consideration in exchange for your
tendered Current Options.

12. If I choose to tender my Current Options for exchange, do I have to tender
all of my Current Options?

Yes. You must tender all of your Current Options for exchange if you want
to participate in this Offer. In other words, you may not tender some of your
Current Options and keep the balance of your Current Options. If you wish to
tender any of your Current Options, you must tender all of your Current Options.

13. May I tender options I have already exercised?

No. The Offer only pertains to unexercised, outstanding options and does
not in any way apply to shares purchased, whether upon the exercise of options
or otherwise. If you have exercised an option in its entirety, that option is no
longer outstanding and is therefore not subject to the Offer. If you have
exercised a Current Option in part, the remaining unexercised portion of that
option is outstanding and may be tendered for exchange pursuant to the Offer.
Options for which you have properly submitted an exercise notice prior to the
date the Offer expires will be considered exercised to that extent, whether or
not you have received confirmation of the exercise or the shares purchased.

14. Will I be required to give up all my rights to the cancelled options?

Yes. Once we have accepted for exchange your tendered Current Options, all
of your Current Options will be cancelled and you will no longer have any rights
under those options. We intend to cancel all options accepted for exchange on
the first day following the expiration of the Offer. We expect the Cancellation
Date to be June 15, 2002.

15. How can I find out the details of my options that are eligible for this
Offer?

Along with this Offer, you will receive a personal stock option statement
detailing your outstanding options that are eligible for this Offer. You can
call the following telephone number to find out the details of your outstanding
options that are eligible for this Offer: 203-252-5500.

16. How many New Options will I receive in exchange for my tendered options?

The number of New Options to be granted in exchange for Current Options
that are accepted for exchange and cancelled will be determined based on the
grant price of the Current Option as follows:

Grant Price of Current Options Exchange Ratios
------------------------------ ---------------
Less than $15.00 1.5 for 1
$15.00 through $20.99 2 for 1
$21.00 through $26.99 2.5 for 1
$27.00 and higher 3 for 1

The number of New Options will also be subject to adjustments for any
future stock splits, stock dividends and similar events, in accordance with the
terms of the applicable Option Plan:

EXAMPLE

To illustrate how the exchange ratios work, we'll assume that you have 4
Current Options for 100 shares each. The grant prices of these 4 Current Options
are: $14.00, $17.00, $23.00, and $29.00. Under these facts, the table below
shows the number of shares subject to each New Option you would receive were you
to participate in the Offer:

Current Options Grant Price Exchange Ratios New Options
- -------------------------- ------------------------ ------------------------ -----------------------

100 $14.00 1.5 for 1 67
100 $17.00 2 for 1 50
100 $23.00 2.5 for 1 40
100 $29.00 3 for 1 33

17. What happens if I do not accept the Offer?

If you choose not to tender your options for exchange, your options will
remain outstanding and retain their current grant prices and other current
terms. We currently expect that we will accept all properly tendered Current
Options promptly after the expiration of this Offer.

18. When will I receive my New Options?

We will grant the New Options on the first business day which is at least
six months and one day after the date we cancel the Current Options accepted for
exchange (the "Grant Date"). Under no circumstances will we grant the New
Options prior to the Grant Date. If we cancel tendered Current Options on June
15, 2002, which is the scheduled date for the cancellation of the options (the
first day following the Expiration Date of the Offer), the New Options will be
granted on or after December 16, 2002. You must continue to be an employee of
Trenwick or one of its Participating Subsidiaries on the Grant Date to be
eligible to receive the New Options.

19. Why won't I receive my New Options immediately after the Expiration Date of
the Offer?

If we were to grant the New Options on a date which is sooner than six
months and one day after the date we cancel the Current Options tendered for
exchange, we could be required under the financial accounting rules applicable
to us to recognize significant charges in our financial statements which would
reduce our reported earnings for each fiscal quarter that the New Options
remained outstanding. This could have a negative impact on our share price.

20. What will be the grant price of the New Options?

The grant price of the New Options will be equal to the closing sale price
of Trenwick common shares on the New York Stock Exchange on the date of grant of
the New Options. Because the New Options will be granted at least six months and
one day following the date the Current Options are cancelled, we cannot predict
the grant price of the New Options. Accordingly, the New Options may have a
higher grant price than some or all of your Current Options that are cancelled.
We recommend that you obtain current market quotations for our common shares
before deciding whether to tender your Current Options.

21. When will the New Options vest?

The New Options will vest two years after the Grant Date. Accordingly, you
may lose the benefit of any vesting under your tendered Current Options that are
accepted for exchange and cancelled.

For example, if you cancel a Current Option that has already vested or
that would vest prior to the Grant Date, the New Options you receive in exchange
for your Current Options will not be vested on the date of grant of such New
Options or for two years after the date of grant.

22. What if my employment terminates before the New Options vest?

If your employment terminates before the New Options vest for any reason,
you will forfeit your New Options upon your termination of employment because
your New Options have not vested.

23. When will the New Options expire?

The New Options will expire on the five year anniversary of the Grant
Date. This may be longer or shorter than the remaining term of the surrendered
Current Options.

24. Will the terms and conditions of my New Options be the same as the terms and
conditions of my Current Options?

The New Options will be issued under the same Option Plan as the related
Current Option cancelled in the Offer. While the New Option will have a new
grant price, Grant Date, term and vesting schedule and will cover a

fewer number of common shares, the other terms and conditions of a New Option
will be substantially identical to the Current Option it replaces. All of the
New Options will be issued as non-qualified stock options for purposes of the
Internal Revenue Code of 1986, as amended.

25. Why don't we simply change the grant price of the Current Options?

Repricing outstanding options could require us under the financial
accounting rules applicable to us to recognize significant charges in our
financial statements that would reduce our reported earnings for each fiscal
quarter that the repriced options remained outstanding. This could have a
negative impact on our share price.

26. Why can't I just be granted more options without having my Current Options
cancelled?

We strive to balance the need for a competitive compensation package for
our employees with the interests of our shareholders. Because of the number of
options that we have currently outstanding, a large grant of new options would
be dilutive to our shareholders and could have a dilutive effect on our earnings
per share.

27. Will I have to pay taxes if I exchange my Current Options in the Offer?

If you exchange your Current Options for New Options, you will not be
required under current U.S. law to recognize income for U.S. Federal income tax
purposes at the time of the tender or upon our acceptance and cancellation of
the Current Options. We believe that the exchange will be treated as a
non-taxable exchange. Further, at the date of grant of the New Options, we
believe that you will not be required under current U.S. law to recognize income
for U.S. Federal income tax purposes.

All Eligible Employees, including those subject to taxation in a foreign
jurisdiction, whether by reason of their nationality, residence or otherwise,
should consult with their own personal tax advisors as to the tax consequences
of their participation in the Offer. Tax consequences may vary depending on each
individual Eligible Employee's circumstances.

Included as part of this Offer is a short summary of the general tax
consequences of the Offer in the United Kingdom. If you are located outside of
the United States, you should consult your own tax advisor regarding your
personal situation before deciding whether or not to participate in the Offer.

28. Will Trenwick grant options to employees during the period beginning on the
date this Offer commences, and ending on the date tendered Current Options are
cancelled?

To avoid any possible adverse accounting consequences, we do not intend to
grant options to Eligible Employees during the period starting on the date the
Offer commences (currently scheduled for May 16, 2002) and ending on the date
tendered Current Options are cancelled (currently scheduled to be June 15,
2002).

29. Will I be considered for additional option grants before the Grant Date of
the New Options?

The focus of our option programs for 2002 is to provide Eligible Employees
with an opportunity for realizing potential value with respect to their Current
Options. At this time, it is our intention not to grant additional options until
after the Grant Date to employees eligible for the Offer. This would apply to
both employees who choose to tender their Current Options, and those who do not.
If Eligible Employees who tender their Current Options that are cancelled in
this Offer were granted options prior to the Grant Date, we may be required
under financial accounting rules applicable to us to recognize significant
charges in our financial statements. We anticipate returning to a more
traditional option granting pattern after the Grant Date, currently scheduled to
be December 16, 2002.

30. What happens if I tender my Current Options and I am on a leave of absence
on the New Option Grant Date?

If you tender your Current Options and they are cancelled and you are on a
leave of absence that is an "authorized leave of absence" on the Grant Date, you
will be entitled to a grant of New Options only if you return to

active employment with Trenwick or one of its Participating Subsidiaries prior
to the first anniversary of the Grant Date. In that event, you will receive a
grant of New Options on the date you return to active employment. The grant
price of the New Options will be equal to the closing sale price of Trenwick
common shares on the New York Stock Exchange on the date your New Options are
granted.

31. What types of leave of absence are considered "authorized leaves of
absences"?

An authorized leave of absence is a leave of absence that has been
approved in accordance with policy or practice by Trenwick or the Participating
Subsidiary that employs you, at the end of which it is expected that you will
return to active employment with Trenwick or one of its Participating
Subsidiaries. By way of example, authorized leaves include approved family
leave, jury duty leave, and military leave.

32. After the grant of my New Options, what happens if the market price of
Trenwick's common shares goes below the grant price for those New Options?

We are making this Offer only at this time and due to the unusual stock
market conditions that have affected many companies. This is a unique, one-time
Offer and you should take this into account in deciding whether to participate
and tender your Current Options.

Trenwick is not providing and is not in a position to provide any
assurances or predictions as to the market price of our common shares at any
time in the future.

33. What happens if Trenwick merges into or is acquired by another company?

If we merge into or are acquired by another company prior to the
expiration of the Offer, you may withdraw your tendered Current Options and have
all the rights afforded you to acquire our common shares under the existing
agreements evidencing those options.

If we are merged into another entity after your tendered Current Options
are accepted for exchange and cancelled but before the New Options are granted,
the surviving company would automatically assume Trenwick's obligations with
respect to the Offer. The type of security and the number of shares subject to
each New Option would be determined by the acquisition agreement between us and
the acquirer based on the same principles applied to the handling of the options
to acquire our common shares that are outstanding at the time of the
acquisition. As a result of the ratio in which our common shares may convert
into an acquirer's common shares in an acquisition transaction, you may receive
options for more or fewer of the acquirer's common shares than the number of
common shares you would receive if you had not participated in the Offer.

If we are acquired and become a subsidiary of the acquiring corporation
after your tendered options are accepted for exchange and cancelled, but before
the New Options are granted, the obligations of Trenwick in connection with the
Offer would not be automatically assumed by the acquiring company. While we may
seek to make provision for tendering option holders in the acquisition
agreement, we cannot guarantee what, if any, provision would be made. As a
result, we cannot guarantee that any New Options would be granted in the event
of such an acquisition.

34. When does the Offer expire? Can the Offer be extended, and if so, how will I
be notified if it is extended?

The Offer expires on June 14, 2002, at 11:59 P.M., Eastern Time (U.S.),
unless we extend it.

Although we do not currently intend to do so, we may, in our discretion,
extend the Offer at any time. If the Offer is extended, we will make an
announcement of the extension no later than 9:00 A.M., Eastern Time (U.S.) on
the business day immediately following the previously scheduled expiration date
of the Offer. If the Offer is extended, then the Cancellation Date for tendered
Current Options accepted for exchange and the Grant Date of the New Options may
be extended if necessary to avoid the possibility that we would have to
recognize any charges in our financial statements which would reduce our
reported earnings. Under the accounting rules applicable to us, the

New Options must be granted at least six months and one day following the date
tendered Current Options are cancelled.

35. Do I have to participate in the Offer?

No. You do not have to participate in this Offer and there are no
repercussions if you choose not to participate. Again, it is entirely up to you
and we cannot advise you of what action to take.

36. What happens to my Current Options if I decide not to participate in the
Offer?

If you elect not to tender your Current Options, they will remain
outstanding until they terminate or expire by their terms. They will retain
their current grant price.

37. What do I need to do to participate in the Offer?

To participate in the Offer, your properly completed election must be
received by us no later than 11:59 P.M., Eastern Time (U.S.) on June 14, 2002
(or such later date and time if we extend the expiration of the Offer). Your
election must be made in one of the following two ways:

o Fax. You may participate by faxing a properly completed, signed and
dated Election Form to the following number: 203-353-5550.

o Mail. You may participate by mailing a properly completed, signed
and dated Election Form in a stamped envelope to the following
address: Trenwick Group Ltd. c/o Trenwick Services Inc., One
Canterbury Green, Stamford, CT 06901, U.S.A., Attn: Legal
Department.

This is a one-time offer. We will strictly enforce the tender offer
period. We reserve the right to reject any or all tenders of options that we
determine are not in appropriate form or that we determine are unlawful to
accept. Subject to our right to extend, terminate and amend the Offer, we
presently expect that we will accept all properly tendered options promptly
after the expiration of the Offer.

38. Can I change my election?

You may change your election to participate in the Offer only one time by
submitting your change no later than 11:59 P.M., Eastern Time (U.S.) on June 14,
2002 (or such later date and time if we extend the expiration of the Offer).

You must change your election with respect to all of your tendered Current
Options; you may not change your election with respect to only a portion of your
Current Options. Also, if you change your election, you may not again tender
your Current Options under the Offer.

To change your election, Trenwick must receive your change in one of the
following two ways:

o Fax. You may change your election by faxing a properly completed,
signed and dated Change Form to the following number: 203-353-5550.

o Mail. You may change your election by mailing a properly completed,
signed and dated Change Form in a stamped envelope to the following
address: Trenwick Group Ltd. c/o Trenwick Services Inc., One
Canterbury Green, Stamford, CT 06901, U.S.A., Attn: Legal Department

You may only change your election one time. If you elect to tender your
Current Options and then change your election, you will not be able to
participate in the Offer.

In addition, if Current Options are properly tendered but for whatever
reason Trenwick is unable to accept the tender by July 12, 2002, you may
withdraw your tender of the Current Options on or after that date.

39. If I choose not to participate in the Offer, what do I have to do?

Nothing. You do not have to file or deliver any forms or letters if you
choose to keep your Current Options and not participate in the Offer.

40. What will happen if I do not elect to participate in the Offer by the end of
the tender offer period?

If you do not elect to participate in the offer by the Expiration Date of
the Offer, you cannot participate in the Offer. There can be no exceptions to
this deadline.

41. What does Trenwick and its Board of Directors think of this Offer?

Although our Board of Directors has approved the making of this Offer,
neither we nor our Board of Directors makes any recommendation as to whether you
should participate or not participate in the Offer. You must make your own
decision whether to participate in the Offer.

Our directors and the Chairman, President and Chief Executive Officer are
not eligible to participate in the Offer.

42. How should I decide whether or not to participate?

We understand that this will be an important decision for all Eligible
Employees. Tendering Current Options under the Offer involves risk as there is
no guarantee or assurance as to our future common share price performance. The
decision to participate must be your personal decision, and will depend largely
on your assessment of your Current Option holdings, and your assumptions about
the future overall economic environment, performance of our business, the stock
market and our common share price, including your assumptions about the common
share price on the Grant Date of the New Options (currently expected to be
December 16, 2002), which will be the grant price of the New Options, and the
common share price thereafter.

You should read all the information provided to you in the Offer,
including certain financial and other information described under the headings
"The Offer: 18. Additional Information" and "The Offer: 19. Summary Financial
Information."

43. Who can I talk to if I have questions about the Offer?

Any questions or additional copies of any documents referred to in the
Offer may be directed to 203-353-5500, Trenwick cannot and will not provide you
any advice regarding your decision whether to tender your Current Options.

44. Does this Offer cover stock appreciation rights?

No.

CERTAIN RISKS OF PARTICIPATING IN THE OFFER

Participation in the Offer involves a number of potential risks, including
those described below. This section briefly highlights some of the risks and is
necessarily incomplete. Eligible Employees should carefully consider these and
other risks and are encouraged to speak with an investment and tax advisor as
necessary before deciding to participate in the Offer. In addition, we strongly
urge you to read the remainder of this Offer to Exchange and the Election
Package before deciding to participate in the Offer. The list of risks does not
include certain risks that may apply to Eligible Employees who live and work
outside of the United States. We urge those employees to read any sections in
this Offer to Exchange discussing tax consequences in their country, as well as
the other documents listed above, and to consult with an investment and tax
advisor as necessary before deciding to participate in this Offer.

1. Economic Risks

If our common share price increases after the date your tendered Current
Options are cancelled, your cancelled Current Options might have been worth more
than the New Options that you will receive in exchange for them.

For example, if you cancel a Current Option with a $13.00 grant price, and
Trenwick's common share price appreciates to $15.00 per share when the New
Options are granted, your New Option will have a higher grant price than your
Current Option and represent the right to purchase fewer common shares than your
Current Option.

Your ability to exercise your New Options may be different than your
ability to exercise your Current Options that are accepted for exchange and
cancelled.

The New Options will vest two years after the Grant Date. This is
different from the vesting under the tendered Current Options. If your Current
Options have vested, you will lose the benefit of any vesting under those
Current Options that are accepted for exchange and cancelled.

In addition, each New Option will have a term of five years. This may be
longer or shorter than the remaining term of the surrendered option it replaces.
If it is shorter than the remaining term of the surrendered option it replaces,
your ability to exercise the New Options will terminate before your ability to
exercise the Current Options that are accepted for exchange and cancelled.

If Trenwick is acquired by or merges with another company, your cancelled
Current Options might have been worth more than the New Options that you will
receive in exchange for them.

These types of transactions could have substantial effects on the price of
our common shares, including potentially substantial appreciation in the price
of our common shares. Depending on the structure of this type of transaction,
tendering Eligible Employees might be deprived of any further price appreciation
in the stock associated with the New Options.

In addition, in the event of an acquisition of our company for stock,
tendering Eligible Employees might receive New Options to purchase shares of a
successor to our company, where the grant price of the New Options would be
equal to the fair market value of such acquirer's stock on the Grant Date.
Eligible Employees who do not tender in the Offer will have their outstanding
Current Options treated in accordance with the terms of the Option Plan they
were granted under and if their Current Options are assumed by the successor to
our company, those options would be priced in accordance with the terms of the
transaction. This could potentially result in a greater financial benefit for
those Eligible Employees who opted not to participate in this Offer and who
instead retained their Current Options.

If your employment terminates prior to the grant of the New Options, you
will receive neither the New Options nor the return of your cancelled Current
Options.

Once your Current Options are cancelled, you will no longer have any
rights with respect to these options. Accordingly, if your employment terminates
for any reason prior to the grant of the New Options, you will not have the
benefit of either the cancelled Current Options or the New Options.

If your employment terminates prior to the time the New Options vest, you
will receive neither the New Options nor the return of your cancelled Current
Options.

The New Options will vest two years after the Grant Date. Accordingly, if
your employment terminates for any reason prior to the time the New Options
vest, you will not have the benefit of either the cancelled Current Options or
the New Options.

If your employment terminates as part of a reduction-in-force prior to the
grant of the New Options, you will receive neither the New Options nor the
return of your cancelled Current Options.

Trenwick's revenues are dependent on the health of the economy and its
relations with brokers and its current and future customers. If the economic
conditions in the United States remain stagnant or worsen or if a wider or
global economic slowdown occurs, our business, operating results, and financial
condition may be materially adversely impacted and we may undertake various
measures to reduce our expenses including, but not limited to,
reductions-in-force of certain of our employees or those of our Participating
Subsidiaries.

If another company acquires Trenwick, that company may, as part of the
transaction or otherwise, decide to terminate some or all of our employees prior
to the grant of New Options under the Stock Option Exchange Program. Termination
for this, or any other, reason before the New Options are granted means that you
will not receive the New Options, nor will you receive any other consideration
for your Current Options that were cancelled.

IF YOUR EMPLOYMENT TERMINATES AS A RESULT OF AN ACQUISITION OR MERGER OF
TRENWICK PRIOR TO THE GRANT OF THE NEW OPTIONS, YOU WILL RECEIVE NEITHER THE NEW
OPTIONS NOR THE RETURN OF YOUR CANCELLED CURRENT OPTIONS.

2. Tax-Related Risks for Non-U.S. Residents

If you are an Eligible Employee residing outside of the U.S. and you take
advantage of this Offer, you may be liable for tax and social insurance
contributions on the fair market value of the New Options. Additionally, you may
lose the ability to claim preferential tax treatment in connection with your New
Options. In addition, you may have exchange control reporting obligations
associated with the transfer of funds in connection with the New Options or the
ownership of foreign shares of stock. A general summary of the tax implications
of the option exchange in the United Kingdom can be found in "The Offer: 15.
Material Tax Consequences for Employees who are Tax Residents in the United
Kingdom." However, this summary is general in nature and necessarily incomplete
and may not apply to your specific circumstances. In addition, tax consequences
change frequently and occasionally on a retroactive basis. We therefore strongly
recommend you consult with a tax advisor in your own country as to the tax
consequences of participating in the Offer.

If you are eligible for the Offer because you live or work in one country
but are also subject to the tax laws in another country, you should be aware
that there may be other tax and social insurance consequences which may apply to
you. You should consult your own tax advisor to discuss these consequences.

3. Business-Related Risks

For a description of risks related to Trenwick's business, please see "The
Offer: 18. Additional Information" and "The Offer: 20. Forward Looking
Statements."

THE OFFER

1. Eligible Employees

Employees are "Eligible Employees" if they: (i) are employed by Trenwick
or a Participating Subsidiary on the date the Offer commences; (ii) hold Current
Options on the date the Offer commences; (iii) remain an employee of Trenwick or
one of its Participating Subsidiaries through the Expiration Date; and (iv) do
not, on or prior to the Expiration Date, elect to terminate their employment or
receive a notice of termination from their employer (individually an "Eligible
Employee"). The Chairman, President and Chief Executive Officer is not eligible
to participate in the Offer and, therefore, is not an Eligible Employee. Also,
the members of Trenwick's Board of Directors are not eligible to participate in
the Offer.

In order to receive the New Options, you must be an employee of Trenwick
or one of its Participating Subsidiaries on the date the New Options are granted
(the "Grant Date") which will be at least six months and one

day after the date the Current Options are cancelled (the "Cancellation Date").
If Trenwick does not extend the Offer, the New Options are scheduled to be
granted on December 16, 2002.

2. Number of Options; Expiration Date

We are offering Eligible Employees the opportunity to exchange all
outstanding, unexercised stock options to purchase our common shares granted
under the Trenwick Group Inc. 1989 Stock Plan, the Trenwick Group Inc. 1993
Stock Option Plan, the Chartwell Re Corporation 1993 Stock Option Plan, the
Chartwell Re Corporation 1997 Omnibus Stock Incentive Plan and the LaSalle Re
Holdings Limited 1996 Long-Term Incentive Plan (together, the "Option Plans" and
individually, an "Option Plan") that are held by them (the "Current Options") in
return for new options that we will grant under the same Option Plan pursuant to
which the cancelled Current Option it replaces was granted (the "New Options").

Unless we extend the Offer, it is scheduled to expire on 11:59 P.M.,
Eastern Time (U.S.), on June 14, 2002 (the "Expiration Date"). See Section 16 of
this Offer to Exchange for a description of our rights to extend, delay,
terminate and amend the Offer. If you accept this Offer, your Current Options
will be cancelled on the first day following the Expiration Date (the
"Cancellation Date"), which is currently scheduled to be June 15, 2002.

To participate in the Offer, you MUST tender all of your Current Options
for cancellation. In other words, you may not tender some of your Current
Options and keep the balance of your Current Options. If you wish to tender any
of your Current Options, you must tender all of your Current Options.

The New Options will be granted on a date that is at least six months and
one day after the Cancellation Date. Assuming we do not extend the Expiration
Date, we presently expect the Grant Date to be no earlier than December 16,
2002.

Our Offer is subject to the terms and conditions described in this Offer
to Exchange. We will only accept Current Options that are properly exchanged and
not validly withdrawn in accordance with Section 5 of this Offer to Exchange
before the Offer expires on the Expiration Date.

Your participation in this Offer is voluntary. If your Current Options are
properly tendered and accepted for exchange, the Current Options will be
cancelled and, subject to the terms of this Offer, you will be entitled to
receive that number of New Options determined as follows, subject to adjustments
for any future stock splits, stock dividends and similar events, in accordance
with the terms of the applicable Option Plan:

For all of your Current Options, the table below shows the number of our
common shares subject to the Current Option that you must exchange for each
common share subject to the New Option, based on the grant price of the Current
Option:

The New Options will be issued under the same Option Plan as the related
Current Option cancelled in the Offer. While the New Option will have a new
grant price, Grant Date, vesting schedule and term and will cover a fewer number
of our common shares the other terms and conditions of a New Option will be
substantially identical to the Current Option it replaces.

If, for any reason, you do not remain an employee of Trenwick or one of
its participating subsidiaries through the date we grant the New Options, you
will not receive any New Options or other consideration in exchange for your
tendered Current Options that have been accepted for exchange. If your
employment terminates after you tendered your Current Options, but prior to the
Expiration Date, you are not eligible to participate in the Offer.

If we decide to take any of the following actions, we will give notice of
such action and keep the Offer open for a period of at least ten business days
after the date of such notification:

(1) we increase or decrease the amount of consideration offered for the
Current Options;

(2) we decrease the number of Current Options eligible to be tendered in
the Offer; or

(3) we increase the number of options eligible to be tendered in the Offer
by an amount that exceeds 2% of the common shares issuable upon exercise of the
options that are subject to the Offer immediately prior to the increase.

For purposes of the Offer, a "business day" means any day other than a
Saturday, Sunday or U.S. federal holiday and consists of the time period from
12:00 midnight through 11:59 P.M., Eastern Time (U.S.).

As of May 14, 2002, options to purchase an aggregate of 1,561,644 common
shares were eligible for exchange under this Offer.

3. Purpose of the Offer

We granted the Current Options outstanding under the Option Plans for one
or more of the following purposes:

o to encourage our employees to act as owners, which helps align their
interests with those of our shareholders

o to reward and motivate our employees for profitable growth; and

o to encourage our employees to continue their employment with us.

Many of our outstanding options, whether or not they are currently vested
and exercisable, have grant prices that are significantly higher than the
current market price of our common shares. We understand that, for our stock
option programs to provide the intended retention and performance incentives for
our employees, employees must feel that our options provide them with an
opportunity to realize value within a reasonable period of time. With the
uncertainty of current market conditions and the decline in the price of our
common shares, we believe that employees may feel that the opportunity for
realizing value is limited with their Current Options. By making this Offer to
Exchange Current Options for New Options that will (1) have a grant price equal
to the closing sale price of our common shares on the New York Stock Exchange on
the Grant Date of the New Options, (2) vest two years from the Grant Date and
(3) have a term of 5 years from the Grant Date, we hope to restore our
employees' confidence in their potential ability to realize value in connection
with their employment with us thereby encouraging our employees to remain with
Trenwick and ultimately maximizing shareholder value.

Neither we nor our Board of Directors makes any recommendation as to
whether you should tender your Current Options, nor have we authorized any
person to make any such recommendation. Note that the New Options may have a
higher grant price, longer vesting and shorter exercise period than some or all
of your Current Options. You are urged to evaluate carefully all of the
information in this Offer and to consult your own investment and tax advisors.

You must make your own decision whether to tender your Current Options for
exchange.

4. Procedures for Participating in the Offer to Exchange

Proper Tender of Options

To validly tender your Current Options through the Offer, your properly
completed election must be received by us no later than 11:59 P.M., Eastern Time
(U.S.) on June 14, 2002 (or such later date and time if we extend the expiration
of the Offer). We will not accept any election received after expiration of the
Offer. Your election must be made in one of the following two ways:

o Fax. You may participate by faxing a properly completed, signed and
dated Election Form to the following numbers: 203-353-5550.

o Mail. You may participate by mailing a properly completed, signed
and dated Election Form in a stamped envelope to the following
address: Trenwick Group Ltd., c/o Trenwick Services Inc., One
Canterbury Green, Stamford, CT 06901, U.S.A., Attn: Legal
Department.

The method of delivery of all documents, including your election to
participate in the Offer, is at your risk. If delivery is by standard mail, we
recommend that you use certified mail with return receipt requested. In all
cases, you should allow sufficient time to ensure timely delivery.

Determination of Validity; Rejection of Current Options; Waiver of Defects; No
Obligation to Give Notice of Defects.

We will determine, in our discretion, all questions as to form, validity,
including time of receipt, eligibility and acceptance of any tender of Current
Options. Our determination of these matters will be final and binding on all
parties. We may reject any or all tenders of Current Options that we determine
are not in appropriate form or that we determine are unlawful to accept or not
timely made. Otherwise, we expect to accept all properly and timely tendered
Current Options which are not validly withdrawn. We may also waive any of the
conditions of this Offer or any defect or irregularity in any tender with
respect to any particular Current Options or any particular Eligible Employee.
No tender of Current Options will be deemed to have been properly made until all
defects or irregularities have been cured by the tendering Eligible Employee or
waived by us. Neither we nor any other person is obligated to give notice of any
defects or irregularities in tenders, and no one will be liable for failing to
give notice of any defects or irregularities.

Our Acceptance Constitutes an Agreement

Your tender of Current Options pursuant to the procedures described above
constitutes your acceptance of the terms and conditions of this Offer and will
be controlling, absolute and final, subject to your withdrawal rights under
Section 5 below and our acceptance of your tendered Current Options in
accordance with Section 6 below. Our acceptance for exchange of your Current
Options tendered by you pursuant to this Offer will constitute a binding
agreement between us and you upon the terms and subject to the conditions of
this Offer.

Subject to our rights to extend, terminate and amend the Offer, we
currently expect that we will accept promptly after the expiration of the Offer
all properly tendered Current Options that have not been validly withdrawn.

5. Withdrawal Rights

You may only withdraw your tendered Current Options, and thus change your
election to participate, in accordance with the provisions of this Section 5. In
addition, if Current Options are properly tendered but for whatever reason
Trenwick is unable to accept the tender by July 12, 2002, you may withdraw your
tender of the Current Options on or after that date.

You may withdraw your tendered Current Options at any time prior to 11:59
P.M., Eastern Time (U.S.) on June 14, 2002. If we extend this Offer beyond that
time, you may withdraw your tendered Current Options at any time until the
extended expiration of this Offer.

If your employment with us terminates prior to the expiration of the
Offer, your tendered Current Options will automatically be withdrawn. Similarly,
if you elect to leave or receive a notice of termination from your employer
prior to the expiration of the Offer, your tendered Current Options will
automatically be withdrawn. If the tender of your Current Options is
automatically withdrawn, you will no longer be eligible to participate in the
Offer, but you may be able to exercise your Current Options pursuant to their
terms.

To validly withdraw your tendered Current Options, and thus change your
election to participate in the Offer, you must do so in one of the following two
ways:

o Fax. You may change your election by faxing a properly completed,
signed and dated Change Form to the following numbers: 203-353-5550.

o Mail. You may change your election by mailing a properly completed,
signed and dated Change Form in a stamped envelope to the following
address: Trenwick Group Ltd., c/o Trenwick Services Inc., One
Canterbury Green, Stamford, CT 06901, U.S.A., Attn: Legal
Department.

Except in accordance with the next sentence, the Change Form must be
executed by the Eligible Employee who tendered the Current Options to be
withdrawn. If the signature is by a trustee, executor, administrator, guardian,
attorney-in-fact, officer of a corporation or another person acting in a
fiduciary or representative capacity, the signer's full title and proper
evidence of the authority of such person to act in such capacity must be
indicated on the Change Form.

You may only change your election one-time. If you elect to tender your
Current Options and then change your election, you will not be able to
participate in the Offer.

Neither we nor any other person is obligated to give notice of any defects
or irregularities in any Change Form, nor will anyone incur any liability for
failure to give any such notice. We will determine, in our discretion, all
questions as to form and validity, including time of receipt, of all changes of
election. Our determination of these matters will be final and binding.

The method of delivery of all documents, including your change of
election, is at your risk. If delivery is by mail, we recommend that you use
certified mail with return receipt requested. In all cases, you should allow
sufficient time to insure timely delivery.

6. Acceptance of Current Options for Exchange and Issuance of New Options

Upon the terms and subject to the conditions of this Offer and promptly
following the Expiration Date, we expect to accept for exchange and cancel
Current Options properly tendered and not validly withdrawn before the
Expiration Date and to notify all Eligible Employees who have tendered their
Current Options of our acceptance. If your tendered Current Options are accepted
and cancelled on June 15, 2002, the first day immediately following the
scheduled Expiration Date of the Offer, you will be granted your New Options on
or promptly after December 16, 2002, which is the first business day that is at
least six months and one day after the date the tendered Current Options are
expected to be accepted for exchange and cancelled. If we extend the date by
which we must accept and cancel Current Options properly tendered, you will be
granted New Options on a subsequent trading day that is on or promptly after the
first trading day that is at least six months and one day after the extended
date of acceptance and cancellation of tendered Current Options.

Consequences of Trenwick Being Acquired

If we merge into or are acquired by another company prior to the
expiration of the Offer, you may withdraw your tendered Current Options and have
all the rights afforded you to acquire our common stock under the existing
agreements evidencing those options.

If we are merged into another entity after your tendered Current Options
are accepted for exchange and cancelled but before the New Options are granted,
the surviving company would automatically assume Trenwick's obligations with
respect to the Offer. The type of security and the number of shares subject to
the each New Option would be determined by the acquisition agreement between us
and the acquirer based on the same principles applied to the handling of the
options to acquire our common shares that are outstanding at the time of the
acquisition. As a result of the ratio in which our common shares may convert
into an acquirer's common shares in an acquisition transaction, you may receive
options for more or fewer of the acquirer's common shares than the number of
shares you would receive if you had not participated in the Offer. In addition,
if you had not participated in the Offer, you may, under the terms of certain
Option Plans, be entitled to a lump sum cash payment for your Current Options.

No Partial Tenders

To participate in the Offer, you must tender all of your Current Options
for cancellation. In other words, you may not tender some of your Current
Options and keep the balance of your Current Options. If you wish to tender any
of your Current Options, you must tender all of your Current Options.

Acceptance of Tendered Options

For purposes of the Offer, we will be deemed to have accepted Current
Options that are validly tendered and are not properly withdrawn when we give
oral or written notice of our acceptance of such options, which will likely be
by press release. Subject to our rights to extend, terminate and amend the
Offer, we currently expect that we will accept promptly after the expiration of
the Offer all properly tendered Current Options that are not validly withdrawn.
When we accept your tendered Current Options for exchange and we cancel those
options, you will have no further rights with respect to those options or under
their corresponding stock option agreements. By tendering your Current Options,
you agree that the applicable stock option agreements will terminate upon our
cancellation of your tendered Current Options. As soon as administratively
practical after we accept and cancel tendered Current Options, we will send each
tendering Eligible Employee a notice indicating the number of shares subject to
the Current Options that we have accepted and cancelled, the number of shares
that will be subject to the New Options and the expected Grant Date of the New
Options.

If you are on an authorized leave of absence on the Grant Date of the New
Options, you will be entitled to a grant of New Options only if you return to
active employment with Trenwick or one of its Participating Subsidiaries prior
to the first anniversary of the Grant Date. In that event, you will receive a
grant of New Options on the day you return to active employment. The grant price
of the New Options will be equal to the closing sale price of Trenwick common
shares on the New York Stock Exchange on the date your New Options are granted.

7. Conditions of the Offer

Notwithstanding any other provision of the Offer, we will not be required
to accept any Current Options tendered for exchange, and we may terminate or
amend this Offer, or postpone our acceptance and cancellation of any Current
Options tendered for exchange, in each case, subject to Rule 13e-4(f) (5) under
the Securities Exchange Act, if at any time on or after May 16, 2002 and before
the Expiration Date, any of the following events has occurred, or has been
determined by us to have occurred, and, in our reasonable judgment in any case
and regardless

of the circumstances giving rise to the event, including any action or omission
to act by us, the occurrence of such event or events makes it inadvisable for us
to proceed with the Offer or with the acceptance and cancellation of the Current
Options tendered for exchange:

(a) there shall have been threatened or instituted or be pending any
action or proceeding by any government or governmental, regulatory
or administrative agency, authority or tribunal or any other person,
domestic or foreign, before any court, authority, agency or tribunal
that directly or indirectly challenges the making of the Offer, the
acquisition of some or all of the tendered Current Options pursuant
to the Offer, the issuance of New Options, or otherwise relates in
any manner to the Offer or that, in our reasonable judgment, could
materially and adversely affect the business, condition (financial
or other), income, operations or prospects of Trenwick or our
subsidiaries or affiliates, or otherwise materially impair in any
way the contemplated future conduct of our business or the business
of any of our subsidiaries or affiliates or materially impair the
contemplated benefits of the Offer to us;

(b) there shall have been any action threatened, pending or taken, or
approval withheld, or any statute, rule, regulation, judgment, order
or injunction threatened, proposed, sought, promulgated, enacted,
entered, amended, enforced or deemed to be applicable to the Offer
or us or any of our subsidiaries or affiliates, by any court or any
authority, agency or tribunal that, in our reasonable judgment,
would or might directly or indirectly:

(1) make the acceptance for exchange of, or issuance of New
Options for, some or all of the tendered Current Options
illegal or otherwise restrict or prohibit consummation of the
Offer or otherwise relates in any manner to the Offer;

(2) delay or restrict our ability, or render us unable, to accept
for exchange, or issue New Options for, some or all of the
tendered Current Options;

(3) materially impair the benefits we hope to receive as a result
of the Offer; or

(4) materially and adversely affect the business, condition
(financial or other), income, operations or prospects of
Trenwick or our subsidiaries or affiliates, or otherwise
materially impair in any way the contemplated future conduct
of our business or the business of any of our subsidiaries or
affiliates or materially impair the contemplated benefits of
the Offer to us;

(1) any general suspension of trading in, or limitation on prices
for, securities on any national securities exchange or in the
over-the-counter market;

(2) the declaration of a banking moratorium or any suspension of
payments in respect of banks in the United States, whether or
not mandatory;

(3) the commencement of a war, armed hostilities or other
international or national crisis directly or indirectly
involving the United States;

(4) any limitation, whether or not mandatory, by any governmental,
regulatory or administrative agency or authority on, or any
event that in our reasonable judgment might affect, the
extension of credit by banks or other lending institutions in
the United States;

(5) any significant decrease in the market price of the shares of
our common stock or any change in the general political,
market, economic or financial conditions in the United States
or abroad that could, in our reasonable judgment, have a
material adverse effect on the business, condition (financial
or other), operations or prospects of Trenwick or our
subsidiaries or affiliates or on the trading in our common
shares;

(6) any change in the general political, market, economic or
financial conditions in the United States or abroad that could
have a material adverse effect on our business, condition
(financial or other), operations or prospects or that of our
subsidiaries or affiliates or that, in our reasonable
judgment, makes it inadvisable to proceed with the Offer;

(7) in the case of any of the foregoing existing at the time of
the commencement of the Offer, a material acceleration or
worsening

(8) any decline in either the Dow Jones Industrial Average, the
Nasdaq National Market or the Standard and Poor's Index of 500
Companies by an amount in excess of 10% measured during any
time period after the close of business on May 16, 2002;

(d) there shall have occurred any change in generally accepted
accounting standards or the application or interpretation thereof
which could or would require us for financial reporting purposes to
record compensation expense against our earnings in connection with
the Offer;

(e) a tender or exchange offer with respect to some or all of our common
shares, or a merger or acquisition proposal for us, shall have been
proposed, announced or made by another person or entity or shall
have been publicly disclosed, or we shall have learned that:

(1) any person, entity or "group," within the meaning of Section
13(d)(3) of the Securities Exchange Act, shall have acquired
or proposed to acquire beneficial ownership of more than 5% of
our outstanding common shares, or any new group shall have
been formed that beneficially owns more than 5% of our
outstanding common shares, other than any such person, entity
or group that has filed a Schedule 13D or Schedule 13G with
the SEC before May 16, 2002;

(2) any such person, entity or group that has filed a Schedule 13D
or Schedule 13G with the SEC before May 16, 2002 shall have
acquired or proposed to acquire beneficial ownership of an
additional 2% or more of our outstanding common shares; or

(3) any person, entity or group shall have filed a Notification
and Report Form under the Hart-Scott-Rodino Antitrust
Improvements Act of 1976 or made a public announcement
reflecting an intent to acquire us or any of our subsidiaries
or any of the assets or securities of us or any of our
subsidiaries; or

(f) any change or changes shall have occurred in our business, condition
inancial or other), assets, income, operations, prospects or share
ownership or that of our subsidiaries or affiliates that, in our
judgment, is or may be material to us or our subsidiaries or
affiliates.

The conditions to the Offer are for our benefit. We may assert them in our
discretion regardless of the circumstances giving rise to them prior to the
Expiration Date. We may waive them, in whole or in part, at any time and from
time to time prior to the Expiration Date, in our discretion, whether or not we
waive any other condition to the Offer. Our failure at any time to exercise any
of these rights will not be deemed a waiver of any such rights. The waiver of
any of these rights with respect to particular facts and circumstances will not
be deemed a waiver with respect to any other facts and circumstances. Any
determination we make concerning the events described in this Section 7 will be
final and binding upon all persons.

8. Price Range of Common Shares Underlying the Current Options

As of September 28, 2000, Trenwick Group Ltd. common shares commenced
trading on the New York Stock Exchange under the ticker symbol TWK. Prior to
such date, LaSalle Re Holdings Limited traded on the New York Stock Exchange
under the ticker symbol LSH. The following table sets forth for the periods
presented below, the high and low sales price of the LaSalle Re Holdings Limited
common shares as reported by the New York Stock

Exchange through September 27, 2000 and of Trenwick Group Ltd. as reported by
the New York Stock Exchange from September 28, 2000 through March 31, 2002.

High Low

2002 Year
Quarter ended March 31, 2001 $10.85 $6.49

2001 Year
Quarter ended March 31, 2001 $25.60 $18.25
Quarter ended June 30, 2001 $25.69 $18.34
Quarter ended September 30, 2001 $23.16 $ 5.50
Quarter ended December 31, 2001 $11.05 $ 6.50

2000 Year
Quarter ended March 31, 2000 $16.38 $11.31
Quarter ended June 30, 2000 $15.50 $12.25
Quarter ended September 30, 2000 $19.44 $13.69
Quarter ended December 31, 2000 $27.13 $14.75

On May 14, 2002, the closing sale price of our common shares on the New
York Stock Exchange was $8.35 per share.

We recommend that you evaluate current market quotes for our common
shares, among other factors, before deciding whether or not to tender your
Current Options.

9. Source and Amount of Consideration; Terms of New Options

Consideration

We will issue New Options to purchase our common shares under the
applicable Option Plan (the same Option Plan under which the related Current
Options were originally granted) in exchange for Current Options properly
tendered and cancelled in the Offer by us, subject to the terms set forth in the
Offer.

The number of New Options to be granted in exchange for Current Options
that are accepted for exchange and cancelled will be determined as follows,
subject to adjustments for any future share splits, share dividends and similar
events, in accordance with the terms of the applicable Option Plan:

For all of your Current Options, the table below shows the number of
common shares subject to the New Option that you will receive in exchange for
the common shares subject to your Current Option based on the grant price of
your Current Option:

We will not issue any New Options exercisable for fractional shares.
Instead, if the exchange conversion yields a fractional amount of shares, we
will round up (.50 or over) or down (.49 or under) to the nearest whole number
of shares with respect to each New Option. Each New Option will entitle the
Eligible Employee to purchase our common shares in accordance with the terms of
the applicable Option Plan.

The issuance of New Options under this Offer will not create any
contractual or other right of the recipients to receive any future grants of
stock options or benefits instead of stock options or any right of continued
employment.

As of May 14, 2002, approximately 2,874,603 options were issued and
outstanding, of which approximately 1,561,644 million options (representing
approximately 54% of all such options) were held by Eligible Employees.

Description of Option Plans and New Options

The following description of the Option Plans and the New Options is only
a summary of some of the material provisions of those documents, but is not
complete. These descriptions are subject to, and qualified in their entirety by
reference to, the actual provisions of the Options Plans. Information regarding
our Option Plans may be found in the S-8 Registration Statements and related
Prospectuses prepared in connection with each of the Option Plans. Please
contact us at 203-353-5500 to request copies of the Option Plans and related
Prospectuses. Copies will be provided promptly at our expense.

The New Options required to be granted under this Offer will be issued
under the following Options Plans: the Trenwick Group Inc. 1989 Stock Plan, the
Trenwick Group Inc. 1993 Stock Option Plan, the Chartwell Re Corporation 1993
Stock Option Plan, the Chartwell Re Corporation 1997 Omnibus Stock Incentive
Plan and the LaSalle Re Holdings Limited 1996 Long-Term Incentive Plan. The
Option Plans permit the grant of non-qualified stock options and stock
appreciation rights.

As of May 14, 2002, there were 124,923, 116,077, 93,369 and 194,399 common
shares available for issuance under the Trenwick Group Inc. 1993 Stock Option
Plan, the Chartwell Re Corporation 1993 Stock Option Plan, the Chartwell Re
Corporation 1997 Omnibus Stock Incentive Plan and the LaSalle Re Holdings
Limited 1996 Long-Term Incentive Plan, respectively. The Trenwick Group Inc.
1989 Stock Plan has expired and presently no options may be granted under this
Option Plan. Our shareholders, however, approved amendments to each Option Plan,
including the Trenwick Group Inc. 1989 Stock Plan, in order to implement this
Offer.

The terms of the New Options are expected to be the same as the related
Current Options cancelled in the exchange, except that (i) the New Options will
be granted on a date that is at least six months and one day after the date the
Current Options are cancelled; (ii) the grant price of the New Options will be
the closing sale price of our common shares on the New York Stock Exchange on
the Grant Date; (iii) the New Options will not vest until the two year
anniversary of the Grant Date; (iv) the New Options will expire on the five year
anniversary of the Grant Date; and (v) the number of shares underlying the New
Options will be determined as described above. Also, in certain countries other
than the United States, the New Options may be subject to different terms and
conditions than the Current Options they replace.

All Current Options subject to this Offer are non-qualified options for
purposes of the Internal Revenue Code of 1986, as amended. All New Options that
may be granted pursuant to this Offer will also be non-qualified options for
purposes of the Internal Revenue Code of 1986, as amended.

The New Options will be subject to the terms and conditions of the Offer,
the Option Plan under which they will be granted, and the option agreement for
the related Current Option, as amended by the Election Package.

This Offer excludes any outstanding stock appreciation rights.

This Offer will have no effect on those options that are not eligible to
participate in this Offer. Those options will remain outstanding in accordance
with and subject to their terms.

Administration

The Compensation Committee (the "Committee") of our Board of Directors
administers the Option Plans, unless it has delegated administration to
Trenwick. The Committee has the authority to construe, interpret and amend the
Option Plans. The Committee determines the employees to whom grants of options
to acquire our common shares are made based on such factors as the Committee may
deem relevant. The Committee also determines, subject to the terms and
conditions of the Option Plans, the terms and conditions of the options,
including the number of options, the effective date of grant, and the option
exercise period and vesting schedule.

Term

The options granted under our Options Plans may not have a term greater
than 10 years. Each New Option will have a five year term. Accordingly, each New
Option may have a term which is longer or shorter than the Current Option for
which it is exchanged.

Termination

Generally, you may exercise the vested portion of your New Option at any
time prior to the date the New Option expires. If, however, your employment with
Trenwick or its subsidiaries or affiliates terminates, the time in which you may
exercise the vested portion of your New Option may be shortened. If your
employment terminates within two years of the date of grant of the New Option
for any reason, you will forfeit the New Option upon your termination of
employment. Thereafter, should you terminate your employment for any reason, you
have a limited time period (between 30 and 60 days) in which to exercise the
vested portion of your New Option. In certain instances, such as death, this
time period may be extended under the terms of the Option Plans.

Termination of Employment Before the Grant Date of the New Options

If, for any reason, you are not an employee of Trenwick or one of its
Participating Subsidiaries from the date you tender your Current Options through
the date the New Options are granted, you will not receive any New Options or
any other consideration in exchange for your tendered Current Options that have
been accepted for exchange. By way of example, this means if you quit, with or
without good reason, or die, or we terminate your employment, with or without
cause, before the date we grant the New Options, you will not receive anything
for the Current Options that you tendered and which we cancelled.

Grant Price

Generally, the Committee determines the grant price at the time an option
is granted under an Option Plan. Our Option Plans generally prohibit the grant
of stock options with a grant price less than the fair market value of the our
common shares on the date the stock option is granted. The grant price of the
New Options will be the closing sale price of our common shares on the New York
Stock Exchange on the date the New Options are granted.

Accordingly, we cannot predict the grant price of the New Options. Your
New Options may have a higher grant price than some or all of your Current
Options.

Vesting

Each option agreement specifies the term of the option and the date when
the option becomes exercisable. The terms of vesting are determined by the
Committee. The Current Options granted under the Option Plans generally vest 20%
per year over the five years after the date they are granted.

The New Options will vest on the second anniversary of the date they are
granted. Accordingly, to the extent that the related Current Options tendered
for exchange have previously vested, you will be exchanging vested Current
Options for unvested New Options.

Payment of Grant Price

You may exercise your New Options, in whole or in part, by contacting us
and following the administrative procedures that have been established. In
addition, you can exercise your stock options by fax or mail. The permissible
methods of payment of the grant price are established under the terms of our
Option Plans and generally include the following:

o cash or check;

o cashless exercise;

o tender to us of common shares having a fair market value on the date
of exercise equal to the aggregate grant price; or

o a combination of the foregoing methods.

Plan Amendment or Termination and Award Amendments

In general, under the Option Plans, the Committee may from time to time
change, suspend or terminate one or more of the Option Plans or amend the terms
of the Options Plans and any outstanding options under the Option Plans,
including amendments to the Option Plans prior to the Grant Date of the New
Options, provided any approvals required under applicable law or stock exchange
rules are obtained and, generally, no amendment, suspension or termination can
be made to outstanding Current Options that would adversely affect the existing
rights of an Eligible Employee without his or her consent. We presently do not
anticipate that the Committee will make any material amendments to the Option
Plans prior to the Grant Date of the New Options other than amendments that the
Committee considers necessary or desirable to implement this Offer and comply
with local tax or regulatory requirements.

Adjustments Upon Certain Events

Appropriate adjustments may be made by the Committee to the number or kind
of shares covered by options, both as to options granted or to be granted,
including the New Options, and to the grant price per share, to give effect to
adjustments to the number of our common shares or types of our securities which
result from certain corporate transactions.

Transferability of Options

In general, the New Options may not be transferred. In some cases,
however, the New Options may, after their issuance, be transferred under the
laws of descent and distribution. In these cases, the New Options may be
exercised by the person who acquires the right to exercise the option by bequest
or inheritance.

No Shareholder Rights or Employment Rights

Eligible Employees have no shareholder rights with respect to any of our
common shares subject to outstanding options until such shares are purchased in
accordance with the provisions of the applicable Option Plan and option
agreement. Nothing in any of the Option Plans confers upon any Eligible Employee
any right to continued employment.

Registration of Common Shares

All of our common shares issuable upon exercise of options under the
Option Plans, including the shares that will be issuable upon exercise of all
New Options to be granted pursuant to the Offer, have been registered under the
Securities Act of 1933, as amended, on a registration statement on Form S-8
filed with the SEC. Unless you are one of our affiliates, you will be able to
sell your common shares issued upon exercise of New Options free of any transfer
restrictions under applicable securities laws.

Tax Consequences

You should refer to "The Offer: 14. Material U.S. Federal Income Tax
Consequences" and "The Offer: 15. Material Tax Consequences for Employees who
are Tax Residents in the United Kingdom" for a discussion of U.S. federal income
tax and U.K. tax consequences of accepting or rejecting this Offer to tender
Current Options for cancellation and of the grant of the New Options under this
Offer to Exchange. We recommend that you consult with your own tax advisor to
determine the tax consequences of the Offer under the laws of the country or
countries in which you are a taxpayer.

This summary of the Option Plans, the Current Options and the New Options
is qualified in its entirety by the specific language of the Option Plans and
applicable option agreement, copies of which are available upon request by
contacting us at 203-353-5500.

10. Information Concerning Trenwick

The address of our principal executive office is Continental Building, 25
Church Street, Hamilton HM12, Bermuda. Our telephone number is 441-292-4985. Our
Internet address on the worldwide web is http://www.trenwick.com. Information
contained on our website does not constitute a part of this Offer to Exchange.
Questions about this Offer or requests for assistance or for additional copies
of this Offer to Exchange or the Election Package should be directed to us at
203-353-5500.

Trenwick is a Bermuda-based specialty insurance and reinsurance
underwriting organization with five distribution platforms operating through its
subsidiaries located in the United States, the United Kingdom and Bermuda.
Trenwick America Re provides treaty reinsurance to insurers of property and
casualty risks in the United States. Trenwick International underwrites
specialty insurance as well as facultative reinsurance on a worldwide basis.
Chartwell Managing Agents is Trenwick's managing agency at Lloyd's. Canterbury
Financial Group underwrites U.S. property and casualty insurance through
specialty program administrators. LaSalle Re is a property and casualty
reinsurer writing worldwide specialist products with an emphasis on catastrophe
coverage.

The financial information included in our annual report on Form 10-K for
the year ended December 31, 2001, and our quarterly report on Form 10-Q for the
quarter ended March 31, 2002, is incorporated herein by reference. See "The
Offer: 18. Additional Information" for instructions on how you can obtain copies
of our SEC filings, including filings that contain our financial statements.

11. Interests of Directors and Executive Officers; Transactions and Arrangements
Concerning the Current Options and our Common Shares

A list of our directors and executive officers is attached to this Offer
to Exchange as Schedule A. As of May 14, 2002, our directors and executive
officers as a group (11 persons) beneficially owned options outstanding under
all of our stock option plans to purchase a total of 1,028,764 common shares,
which represented approximately 36% of the shares subject to all options
outstanding as of that date. The options held by our directors and our Chairman,
President and Chief Executive Officer are not eligible to be tendered in the
Offer. Our remaining executive officers are eligible to participate in the
Offer.

The following table sets forth the beneficial ownership of our continuing
directors and executive officers of options outstanding as of May 14, 2002.

Directors Number of Options
--------- -----------------

W. Marston Becker.......................... 6,250
Anthony S. Brown........................... 7,250
Robert M. DeMichele........................ 8,050
Robert V. Deutsch.......................... 4,000
Clement S. Dwyer, Jr....................... 4,000
Joseph D. Sargent.......................... 9,250
Stephen R. Wilcox.......................... 9,250

Executive Officers
------------------

James F. Billett, Jr....................... 505,370
Paul Feldsher.............................. 163,464
Robert A. Giambo........................... 153,916
Alan L. Hunte 155,964

- ----------
*Less than 0.1%

As part of their annual compensation, we granted each non-employee
director on May 15, 2002 a stock option for 1,000 common shares.

Except as described above, there have been no transactions in options to
purchase our shares or in our shares which were affected during the 60 days
prior to May 16, 2002 by Trenwick or, to the best of our knowledge, by any
executive officer, director or affiliate of Trenwick.

12. Status of Current Options Acquired by Us in the Offer; Accounting
Consequences of the Offer

Many of our Eligible Employees hold Current Options with grant prices
significantly higher than the current market price of our common shares. We
believe it is in our best interest to offer these Eligible Employees an
opportunity to more effectively participate in the potential growth in our share
price. We could accomplish this goal by repricing Current Options, which would
enable Eligible Employees to immediately receive New Options with a grant price
equal to the current market price of our shares determined under the terms of
the Option Plans. However, if we repriced Current Options, we could be required
under the financial accounting rules applicable to us to recognize significant
charges in our financial statements relating to the repriced options which would
reduce our reported earnings for each fiscal quarter that the repriced options
remained outstanding. This could have a negative impact on our share price.

We believe that we can accomplish our goals of providing Eligible
Employees the benefit of choosing whether they want to receive options that over
time may have a greater potential to increase in value, without the accounting
consequence described above because:

o we will not grant any New Options to Eligible Employees who tender
their Current Options in the Offer until a date that is at least six
months and a day from the date we cancel Current Options tendered
for exchange;

o the grant price of all New Options will equal the closing sales
price of our common shares on the New York Stock Exchange on the
Grant Date (determined under the terms of the Option Plans); and

o we will not grant any other options to Eligible Employees until
after the date on which we grant the New Options.

Current Options we accept for exchange and acquire pursuant to this Offer
will be cancelled and will be returned to the pool of options available under
the applicable Option Plan. The New Options will be granted from the same Option
Plan under which the surrendered Current Options were granted. The shares
underlying the cancelled Current Options not used in connection with this Offer
to grant the New Options will be available for future grants to employees and
other eligible plan participants.

13. Legal Matters; Regulatory Approvals

We are not aware of any license or regulatory permit that appears to be
material to our business that might be adversely affected by our exchange of
Current Options and issuance of New Options to Eligible Employees as
contemplated by this Offer, or of any approval or other action by any government
or governmental, administrative or regulatory authority or agency, domestic or
foreign, that would be required for the acquisition or cancellation of our
options as contemplated herein, other than such other approvals as have been or
are expected to be obtained by us. We are unable to predict whether we may be
required to delay the acceptance of Current Options for exchange pending the
outcome of any such matter. We cannot assure you that any such approval or other
action, if needed, would be obtained or would be obtained without substantial
conditions or that the failure to obtain any such approval or other action might
not result in adverse consequences to our business. Our obligation under the
Offer to accept any tendered Current Options for exchange is subject to
conditions, including the conditions described in "The Offer: 7. Conditions of
the Offer."

If we are prohibited by applicable laws or regulations from granting New
Options immediately after the date we expect to grant the New Options (expected
to be December 16, 2002), we will not grant any New Options. We are unaware of
any such prohibition at this time, and we will use reasonable efforts to effect
the grant, but if the grant is prohibited we will not grant any New Options and
you will not get any other consideration for the options you tendered.

14. Material U.S. Federal Income Tax Consequences

The following is a general summary of the tax consequences of the
cancellation of eligible non-qualified options and grant of new non-qualified
options for Eligible Employees subject to tax in United States. This summary is
general in nature and does not discuss all of the tax consequences that may be
relevant to you in light of your particular circumstances, nor is it intended to
be applicable in all respects to all Eligible Employees. Please note that tax
laws change frequently and occasionally on a retroactive basis. We advise all
Eligible Employees considering exchanging their Current Options to consult with
their own tax or financial advisors.

If you are a citizen or resident of another country for local law
purposes, the information contained in this summary may not be applicable to
you. You are advised to review the country specific disclosures below and to
seek appropriate professional advice as to how the tax or other laws in your
country apply to your specific situation.

Option Exchange. We do not believe that you will be required to recognize
any income for U.S. federal income tax purposes solely as a result of the
exchange of a Current Option for a New Option. We believe it is likely the
exchange will be treated as a non-taxable exchange of non-qualified options.

Grant of New Option. You will not be subject to U.S. federal income tax
when the New Option is granted to you.

Exercise of New Option. When you exercise the New Option, you will be
subject to tax on the difference between the fair market value of the shares on
the date of exercise and the grant price.

Sale of Shares. If you acquire shares upon exercise, the subsequent sale
of the shares generally will give rise to capital gain or loss equal to the
difference between the sale price and the grant price plus the income you
recognized upon exercise of the New Option. This capital gain or loss will be
treated as long-term or short-term depending on whether you held the shares for
more than one year following the exercise of the New Option.

Dividends. If you exercise your New Option to purchase shares, you may be
entitled to receive dividends. You will be subject to tax on any dividends
received.

Withholding and Reporting. Withholding and reporting for income and
employment tax are required when you exercise your New Option. You will be
responsible for paying any difference between the actual tax liability and the
amount withheld.

15. Material Tax Consequences for Employees who are Tax Residents in the United
Kingdom

The following is a general summary of the tax consequences of the
cancellation of Current Options and grant of New Options under the exchange
program for Eligible Employees subject to tax in the United Kingdom. As you may
know, income tax laws and regulations are subject to frequent changes. Please
note that this summary is general in nature, it is not intended to serve as
specific tax advice concerning your participation and it may not apply to your
particular situation. The summary may not be applicable if you are a citizen of
another country or are considered a resident of another country for local law
purposes. We advise all Eligible Employees considering exchanging their Current
Options to consult with their own tax or financial advisors.

You should consult your financial and/or tax adviser to determine your
personal tax treatment.

Unapproved New Option Grants. The following tax information applies to
grants of U.K. unapproved New Options under the program.

Option Exchange. We do not believe that you will be subject to tax as a
result of the exchange of a Current Option for the grant of a New Option.

Grant of New Option. You will not be subject to tax when the unapproved
New Option is granted to you.

Exercise of New Option. You will be subject to tax when you exercise your
unapproved New Option. Income tax will be charged on the difference between the
fair market value of the stock on the date of exercise and the grant price paid
(i.e., the spread). Your employer will be responsible for tax withholding under
the Pay As You Earn system ("PAYE") in relation to the tax due on the spread
realized on exercise of your option and for paying the income tax withheld to
the U.K. Inland Revenue on your behalf. You will be required to pay any tax or
National Insurance Contribution liability to your employer within 7 days of your
exercise and neither Trenwick nor your employer will be required to transfer any
shares (or any proceeds resulting from the sale) to you until such payment has
been made. If you fail to pay your employer the income tax due on the spread
within 30 days of the date of exercise of your option, you will be deemed to
have received a further taxable benefit equal to the amount of income tax due on
the spread. This will give rise to a further income tax charge. You may be
liable to pay employees' National Insurance Contributions in relation to the
spread or a proportion of the spread on exercise of your New Option at a rate of
10% on earnings up to (pound)30,420; however, from April 6, 2003, the rate of
employees' National Insurance Contributions will be raised by 1% to 11% up to
the so called "upper earnings limit", and a 1% flat rate of National Insurance
Contributions will be due on all earnings above this limit (currently
(pound)30,420). Your employer will be responsible for withholding employees'
National Insurance Contributions and for paying the amount withheld to the U.K.
Inland Revenue on your behalf.

Sale of Shares. When you sell your shares, you may be subject to capital
gains tax. Tax is due on any increase in the value of the shares realized
between the date on which you exercise an option and the date on which you sell
the shares acquired on exercise of that option. Please note that an annual
exemption is available to set against total gains of ((pound)) 7,700 for the tax
year April 6, 2002 to April 5, 2003 and you may also be able to benefit from
taper relief to reduce your chargeable gain. The rate of taper relief is
dependant upon the number of years during which shares are held and whether the
shares qualify as business assets. Any resulting gain will be liable to United
Kingdom Capital Gains Tax and subject to a highest tax rate of 40% (based on
rates applicable for tax year April 6, 2002 to April 5, 2003).

Dividends. If you exercise an option to purchase shares, you may be
entitled to receive dividends. Any dividends paid will be subject to income tax
in the U.K. and will also be subject to United States federal withholding tax.
You may be entitled to a tax credit against your the U.K. income tax for the
United States federal income tax withheld.

Reporting. Your employer is required to report the details of the exchange
of options, the unapproved New Option grant and any future option exercise on
its annual U.K. Inland Revenue tax return. In addition to your employer's
reporting obligations, you must report details of any liabilities arising from
the exercise of your unapproved New Options and from the sale or disposal of
shares together with details of dividend income to the Inland Revenue on your
personal U.K. Inland Revenue tax return.

You will be responsible for paying any taxes owed as a result of the sale
of the shares or the receipt of any dividend.

16. Extension of Offer; Termination; Amendment

We may, from time to time, extend the period of time during which this
Offer is open and delay accepting any Current Options tendered to us by giving
oral or written notice of the extension to Eligible Employees. If the Offer is
extended, then the Grant Date of the New Options will also be extended if
necessary to ensure that the New Options are granted more than six months and
one day following the date tendered Current Options are cancelled.

We also expressly reserve the right, in our reasonable judgment, prior to
the Expiration Date to terminate or amend the Offer and to postpone our
acceptance and cancellation of any Current Options tendered for exchange upon
the occurrence of any of the conditions specified in "The Offer: 7. Conditions
of the Offer" by giving oral or written notice of such termination, amendment or
postponement to Eligible Employees. Our reservation of the right to delay our
acceptance and cancellation of Current Options tendered for exchange is limited
by Rule 13e-4(f)(5) promulgated under the Securities Exchange Act of 1934, as
amended, which requires that we must pay the consideration offered or return the
Current Options tendered promptly after termination or withdrawal of a tender
offer.

Subject to compliance with applicable law, we further reserve the right,
in our discretion, and regardless of whether any event set forth in "The Offer:
7. Conditions of the Offer" has occurred or is deemed by us to have occurred, to
amend this Offer in any respect, including, without limitation, by decreasing or
increasing the consideration offered to Eligible Employees or by decreasing or
increasing the number of options being sought in the Offer. Amendments to the
Offer may be made at any time and from time to time by an announcement. In the
case of an extension, the amendment must be issued no later than 9:00 a.m.,
Eastern Time (U.S.), on the next business day after the last previously
scheduled or announced Expiration Date. Any announcement made pursuant to the
Offer will be disseminated promptly to Eligible Employees in a manner reasonably
designated to inform Eligible Employees of such amendment. Without limiting the
manner in which we may choose to make an announcement, except as required by
applicable law, we have no obligation to publish, advertise or otherwise
communicate any such announcement other than by issuing a press release.

If we materially change the terms of the Offer or the information
concerning the Offer, or if we waive a material condition of the Offer, we will
extend the Offer to the extent required by Rules 13e-4(d)(2) and 13e-4(e)(3)
under the Securities Exchange Act. These rules require that the minimum period
during which an Offer must remain open following material changes in the terms
of the Offer or information concerning the Offer, other than a change in price
or a change in percentage of securities sought, will depend on the facts and
circumstances, including the relative materiality of such terms or information.

17. Fees and Expenses

We will not pay any fees or commissions to any broker, dealer or other
person for soliciting tenders of Current Options pursuant to this Offer to
Exchange.

18. Additional Information

We have filed with the SEC a Tender Offer Statement on Schedule TO, of
which this Offer to Exchange is a part. This Offer to Exchange does not contain
all of the information contained in the Schedule TO and the exhibits to the
Schedule TO. We recommend that you review the Schedule TO, including its
exhibits, and the following materials which we have filed with the SEC, before
making a decision on whether to tender your Current Options:

(a) Our Annual Report on Form 10-K for the year ended December 31,
2001, filed March 21, 2002; and

(b) Our Quarterly Report on Form l0-Q for the quarter ended March
31, 2002, filed May 15, 2002.

We hereby incorporate by reference additional documents that we may file
with the SEC between the date of this Offer and the Expiration Date of the
Offer. These include annual reports on Form 10-K, periodic reports, such as
quarterly reports on Form 10-Q and current reports on Form 8-K, as well as proxy
statements. In addition, you should review any amendments to our Schedule TO and
the Offer filed with the SEC.

These filings, our other annual, quarterly and current reports, our proxy
statements and our other SEC filings may be examined, and copies may be obtained
at standard fees, at the following SEC public reference rooms:

450 Fifth Street N.W. 500 West Madison Street
Room 1024 Suite 1400
Washington, D.C. 20549 Chicago, Illinois 60661

You may obtain information on the operation of the public reference rooms
by calling the SEC at l-800-SEC-0330. Our SEC filings are also available to the
public without charge on the SEC's Internet site at http://www.sec.gov.

Our common shares are listed for trading on the New York Stock Exchange
under the symbol "TWK."

We will also provide without charge to each person to whom a copy of this
Offer to Exchange is delivered, upon the written or oral request of any such
person, a copy of any or all of the documents to which we have referred, other
than exhibits to such documents (unless such exhibits are specifically
incorporated by reference into such documents). Requests should be directed to
us at 203-353-5500.

As you read the documents referred to in this section, you may find some
inconsistencies in information from one document to another later dated
document. Should you find inconsistencies between the documents, or between a
document and this Offer to Exchange, you should rely on the statements made in
the most recent document. The information contained in this Offer to Exchange
about Trenwick should be read together with the information contained in the
documents to which we have referred you.

19. Summary Financial Information

The following summary financial information is derived from Trenwick's
audited financial statements for the years ended December 31, 2001 and 2000 and
Trenwick's unaudited financial statements for the three months ended March 31,
2002. Eligible Employees should refer to the full financial statements and the
notes to financial statements, which are incorporated in the Offer to Exchange.
"The Offer: 18. Additional Information" explains how to find these documents at
the SEC, including on their website at www.sec.gov. In addition, we will provide
this information without charge to each person to whom a copy of this Offer to
Exchange is delivered on written or oral request made to the address and
telephone numbers set forth above.

Summary Financial Information
(dollars in thousands, except per share data)

December 31,
March 31, -----------------------
2002 2001 2000
--------- --------- ---------
Total assets $ 5,575 $ 4,929 $ 4,229
Total liabilities 4,948 4,287 3,426
Book value per share 13.15 13.52 17.79

Three Months Year Ended
Ended December 31,
March 31, -----------------------
2002 2001 2000
------------ --------- ----------
Total revenues $ 299,338 $ 361,555 $1,030,805
Total expenses 316,232 357,340 1,243,007
Income (loss) before income taxes
and cumulative effect of a
change in accounting principles (16.894) -- --
Income (loss) before income tax
and other minority interest -- 4,215 (212,202)
Net income (loss) available to
to common shareholders (1.324) 9,751 (154,347)
Basic and diluted earnings (loss)
per common share (0.04) (0.21) (4.19)

See full financial statements and notes to financial statements referred to
above.

20. Forward-Looking Statements

This Offer to Exchange and our SEC reports referred to above include
"forward-looking statements." When used in this Offer to Exchange, the words
"could," "may," "anticipates," "believes," "estimates," "expects," "intends,"
"plans" and similar expressions as they relate to Trenwick or our management are
intended to identify these forward-looking statements. Forward-looking
statements, including statements concerning Trenwick's

expectations, business prospects, anticipated economic performance, financial
condition and other similar matters, including without limitation, the matters
discussed under the heading "Certain Risks of Participating in the Offer," are
subject to risks and uncertainties, which could cause actual results to differ
materially from those discussed in the forward-looking statements.
Forward-looking statements speak only as of the date of the documents in which
they are made. Trenwick disclaims any obligation or undertaking to provide any
update or revision to any forward-looking statement made by it to reflect any
change in Trenwick's expectations or any change in events, conditions or
circumstances on which the forward-looking statement is based. You should not
place undue reliance on forward-looking statements.

21. Miscellaneous

We are not aware of any country where the making of this Offer is not in
compliance with applicable law. If we become aware of any country where the
making of the Offer is not in compliance with any applicable law, we will make a
good faith effort to comply with such law. If, after such good faith effort, we
cannot comply with such law, the Offer will not be made to, nor will tenders be
accepted from or on behalf of, the Eligible Employees residing in such country.

We have not authorized any person to make any recommendation on our behalf
as to whether you should tender or refrain from tendering your Current Options
pursuant to the Offer. You should rely only on the information contained in this
document or to which we have referred you. We have not authorized anyone to give
you any information or to make any representations in connection with the Offer
other than the information and representations contained in this Offer to
Exchange or the Election Package. If anyone makes any recommendation or
representation to you or gives you any information, you must not rely upon that
recommendation, representation or information as having been authorized by us.

SCHEDULE A

INFORMATION CONCERNING THE CONTINUING DIRECTORS AND EXECUTIVE OFFICERS OF
TRENWICK

Directors
---------

Name Position
- --------------------------------------------- ------------------
W. Marston Becker............................ Director
Anthony S. Brown............................. Director
Robert M. DeMichele.......................... Director
Robert V. Deutsch............................ Director
Clement S. Dwyer, Jr......................... Director
Joseph D. Sargent............................ Director
Frederick D. Watkins......................... Director
Stephen R. Wilcox............................ Director

Executive Officers
------------------

Name Position
- --------------------------------------------- ------------------------------------------------------------------

James F. Billett, Jr......................... Chairman, President and Chief Executive Officer

Paul Feldsher................................ Executive Vice President and Chief Underwriting Officer

Robert A. Giambo............................. Executive Vice President and Chief Actuary

Alan L. Hunte................................ Executive Vice President and Chief Financial Officer
- -------------------------------------------------------------------------------------------------------------------

The address and telephone number of each director and executive officer is:
Trenwick Group Ltd., Continental Building, 25 Church Street, Hamilton HM12,
Bermuda. 441-292-4985.