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                                                                    EXHIBIT 10.9

                                  TYCOM LTD.

                    SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN

                                 PLAN DOCUMENT

                            As of October 1, 2000
                            ---------------------

     1.  Introduction.
         ------------

          (a) The name of this plan is the TyCom Ltd. Supplemental Executive
Retirement Plan.  The Plan is intended to make up for contributions that cannot
be made on behalf of certain key employees under the Savings Plan by reason of
the Limitation.  The Plan shall be construed consistent with the purposes
described herein, including without limitation, the anti-conditioning rules of
Section 401(k)(4) of the Code.

          (b) The Plan is intended to be "a plan which is unfunded and is
maintained by an employer primarily for the purpose of providing deferred
compensation for a select group of management or highly compensated employees"
within the meaning of Sections 201(2), 301(a)(3) and 401(a)(1) of ERISA.

     2.  Definitions.  Wherever used herein, the following terms have the
         -----------
meanings set forth below, unless a different meaning is clearly required by the
context.  Any capitalized term not defined herein shall have the meaning given
to it in the Savings Plan.

          (a) "Account" means the bookkeeping account maintained for each
Participant to which amounts credited on behalf of the Participant under Section
3 shall be recorded.

          (b) "Affiliated Entity" means any entity considered to be in the same
controlled group (within the meaning of Section 302(d)(8)(C) of ERISA) as TyCom
Ltd.
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          (c) "Beneficiary" means the individual(s) designated by the
Participant to receive any benefits due upon or after his or her death pursuant
to Section 8.  In the absence of an effective Beneficiary designation at the
time of the Participant's death, the Participant's Beneficiary shall be his or
her spouse, or if the Participant does not have a spouse at the date of his or
her death, then to the Participant's executors or administrators.

          (d) "Board of Directors" means the Board of Directors of TyCom Ltd.

          (e) "Change in Control" means the occurrence of any of the following
events:

               (i) any "person" or "group" (as defined under Sections 13(d) and
     14(d) of the Securities Exchange Act of 1934 (the "Exchange Act")) is or
     becomes the direct or indirect "beneficial owner" (as defined in Rules 13d-
     3 and 13d-5 under the Exchange Act) of securities representing 50 percent
     or more of the combined voting power of the Company's then outstanding
     voting securities other than in connection with a merger, amalgamation,
     scheme of arrangement or other combination pursuant to which the
     shareholders of the Company immediately prior to such event beneficially
     own 50 percent or more of the voting rights exercisable generally of any
     such person which is an entity;

               (ii) such time as the Continuing Directors (as defined below)
     cease for any reason, other than death, incapacity or retirement of a
     Director, to constitute a majority of the Board of Directors (or, if
     applicable, the Board of Directors of a successor corporation to the
     Company), where the term "Continuing Director" means at any date a member
     of the Board of Directors who (A) was a member of the Board of

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     Directors on the consummation of the first fully underwritten, firm
     commitment public offering pursuant to an effective registration statement
     under the Securities Act of 1933 covering the offer and sale by the Company
     of its equity securities, or such other event as a result of or following
     which the Company's stock shall be publicly held, or (B) was nominated or
     elected subsequent to such date by at least a majority of the Directors who
     were Continuing Directors at the time of such nomination or election or
     whose election to the Board of Directors was recommended or endorsed by at
     least a majority of the Directors who were Continuing Directors at the time
     of such nomination or election; provided, however, that there shall be
     excluded from clause (B) any individual whose election to the Board of
     Directors occurred as a result of a meeting of the Company requisitioned
     pursuant to Section 74 of the Companies Act 1987 of Bermuda or otherwise as
     a result of action taken by or on behalf of a person other than the Board
     of Directors;

               (iii)  any "person" or "group" (other than an employee benefit
     plan or plans maintained by the Company or an Affiliate Entity) comes to
     possess, directly or indirectly, the legal right to direct the management
     and policies of the Company, whether through the ownership of securities,
     by contract or otherwise (other than solely by virtue of membership on the
     Board of Directors or any Committee thereof);

               (iv) a merger, amalgamation, scheme of arrangement or other
     combination of the Company with or into another person or any analogous or
     similar transaction or event occurs as a result of which the voting rights
     exercisable at general meetings of the Company in respect of the shares of
     the Company in issue immediately

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     prior to the relevant event no longer represent a majority of all the
     voting rights normally exercisable at general meetings of the Company (or,
     if the Company is acquired by another entity in connection with such event,
     of such entity) in respect of the shares of the Company (or, if the Company
     is acquired by another entity in connection with such event, of the
     securities of such entity) in issue immediately after such event.

Notwithstanding anything in the foregoing to the contrary, any offering or
series of offerings of the shares of the Company on an established securities
market or exchange or any distribution of shares by Tyco, whether by dividend,
spinoff or otherwise, shall not be considered a "Change in Control."

          (f) "Code" means the Internal Revenue Code of 1986, as amended, and
any successor code, and related rules, regulations and interpretations.

          (g) "Committee" means the Tyco Retirement Committee.

          (h) "Company" means TyCom Ltd. and any successor to all or a major
portion of its assets or business which assumes the obligations of TyCom Ltd.

          (i) "Compensation" means, with respect to any Participant, direct cash
compensation paid during the calendar year to that Participant by the Company or
an Affiliated Entity for services rendered, including salaries, commissions and
bonuses, in each case as determined by the Committee, and including any amount
which would have been paid to the Participant but for an election under the
Savings Plan, or a cafeteria plan under Section 125 of the Code, but excludes
any amounts paid from this Plan, income from the exercise of non-qualified stock
options or from the disqualifying disposition of incentive stock options, income

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realized when restricted stock becomes fully transferable or is no longer
subject to a substantial risk of forfeiture, reimbursement for moving expenses
and other relocation expenses, mortgage interest differentials, payment for
reimbursement for taxes, international assignment premiums, allowances and any
other reimbursements.  Subject to the foregoing limitations, "Compensation"
shall include Compensation from sources within the United States as described in
Section 861 of the Code, and Compensation from sources without the United States
as described in Section 862 of the Code.

          (j) "Determination Date" means the last day of each Plan Year and such
other dates selected by the Committee from time to time.

          (k) "Disability" means a Participant's permanent and total incapacity
of engaging in any employment for the Company or any Affiliated Entity for
physical or mental reasons.  Disability shall be deemed to exist only when such
Participant meets either the requirements for disability benefits under the
Social Security law then in effect, or the requirements for disability benefits
under a long-term disability plan maintained by the Company or an Affiliated
Entity.

          (l) "Eligible Employee" means each employee of the Company, who is not
also an employee of an Affiliated Entity, with Compensation equal to or greater
than the Limitation.  With regard to the credit provided by Section 3(c), the
term "Eligible Employee" also means an employee subject to the limitations
imposed by Section 415 of the Code.

          (m) "ERISA" means the Employee Retirement Income Security Act of 1974,
as amended and any successor statute, and related rules, regulations and
interpretations.

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          (n) "Limitation" means the limitation amount imposed under Section
401(a)(17) of the Code ($170,000 for 2000).

          (o) "Participant" means any Eligible Employee.  Notwithstanding the
foregoing, any individual who was a Participant in a prior Plan Year but who
ceases to be an Eligible Employee shall continue to be a Participant so long as
amounts remain credited to his or her Account, but he or she shall cease to be a
Participant for purposes of receiving Participant Credits under Section 3.

          (p) "Plan" means the TyCom Ltd. Supplemental Executive Retirement
Plan.

          (q) "Plan Year" means the twelve-month period ending on each December
31st.

          (r) "Quarter" means each of the three-month periods ending on March,
June, September and December in each Plan Year.

          (s) "Retirement" or "Retires" shall mean severance from employment
from the Company and all Affiliated Entities for any reason other than a leave
of absence or death on or after the earlier of the attainment of (i) age 65 or
(ii) age 55 and ten Years of Service.

          (t) "Savings Plan" means any so-called "401(k) plan" to which the
Company makes contributions from time to time for the benefit of its employees.

          (u) "Tyco" means Tyco International (US) Inc.

          (v) "Tyco Plan" means the Tyco International (US) Inc. Supplemental
Executive Retirement Plan.

          (w) "Year of Service" means each "Year of Vesting Service" credited to
the Participant under the Savings Plan.

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     3.  Participant Credits.
         -------------------
          (a) Within 60 days following a Determination Date, the Company shall
credit to each Participant's Account an amount determined as follows:

     W = (X times Y) minus Z, where:

     W = the amount to be credited to a Participant's Account pursuant to this
          Section 3(a) with respect to such Determination Date;

     X = the amount by which such Participant's Compensation exceeds the
          Limitation as of such Determination Date;

     Y = a percentage determined in accordance with the following schedule,
          based on the number of years of Service completed by such Participant:

          Years of Service    Percentage
          ----------------    ----------
          Less than 10           5%
          10 - 19                6%
          20 - 24                7%
          25 - 29                8%
          30 or more             9%

          and;

     Z = the amount previously credited to such Participant's Account under this
          Section 3(a) with respect to such Plan Year.

          (b) Notwithstanding the foregoing, the Company reserves the right to
adjust the credits to any Participant's Account if the Participant's
Compensation for the Plan Year is less than the limit imposed by Section
401(a)(17) of the Code.

          (c) The Company shall credit to each eligible Participant's Account an
amount equal to the TSSL Special Pension Supplement which would be credited to
the account of the Participant under the Savings Plan, but disregarding the

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Limitation and disregarding the limitations imposed under Section 415 of the
Code, less the TSSL Special Pension Supplement actually credited to the
Participant's Account under the Savings Plan.  A separate bookkeeping account
shall be maintained for amounts credited to a Participant's Account, and the
credited earnings and losses thereon, until such time as the Participant is
fully vested in the total of all his or her Accounts pursuant to Section 5.

          (d) With respect to each Participant who was a participant in the Tyco
Plan, effective as of October 1, 2000, with such Participant's consent,
the Company may transfer from the Tyco Plan to such Participant's Account under
the Plan an amount equal to the amount credited to the Participant's Account in
the Tyco Plan.  Any transfer of such amount to a Participant's Account pursuant
to this paragraph (d) shall be in lieu of maintaining such credits under the
Tyco Plan.

     4.  Crediting Earnings and Losses.  In accordance with, and subject to, the
         -----------------------------
rules and procedures that are established from time to time by the Committee, in
its sole discretion, amounts shall be credited or debited to a Participant's
Account in accordance with the following rules:

          (a) Election of Measurement Funds.  Each Participant, including former
              -----------------------------
Participants with Accounts, shall elect the manner of deemed investment of all
amounts credited to his or her Account among the Measurement Funds (as described
in Section 4(c) below).  By such election, the Participant may (but is not
required to) add or delete one or more Measurement Funds to be used to determine
the additional amounts to be credited to his or her Account balance, or to
change the portion of his or her Account allocated to each previously or newly
elected Measurement Fund.  Such an election under this Section 4 may be made on
a daily basis

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through the voice response system provided by the Committee's administrative
delegate (or through such other system designated by the Committee) and shall be
effective as soon as reasonably possible thereafter. Such an election must be in
accordance with any and all rules and regulations established by the Committee
for this purpose. Any election made hereunder shall continue to be effective
until properly revoked by the Participant.

          (b) Proportionate Allocation.  In making any election described in
              ------------------------
Section 4(a) above, the Participant shall specify, in increments of 1%, the
percentage of his or her Account to be allocated to a Measurement Fund (as if
the Participant were making an investment in that Measurement Fund with that
portion of his or her Account).

          (c) Measurement Funds.  The Participant may elect one or more of the
              -----------------
Measurement Funds (the "Measurement Funds") identified in Appendix A, attached
hereto and made a part hereof, for the purpose of crediting additional amounts
to his or her Account.  As necessary, the Committee may, in its sole discretion,
discontinue, substitute or add a Measurement Fund.

          (d) Crediting or Debiting Method.  The performance of each elected
              ----------------------------
Measurement Fund (either positive or negative) will be determined by the
Committee, in its sole discretion, based on the performance of the Measurement
Funds themselves.  A Participant's Account shall be credited or debited as of
the end of each business day based on the performance of each Measurement Fund
elected by the Participant, as determined by the Committee in its sole
discretion.

          (e) No Actual Investment.  Notwithstanding any other provision of this
              --------------------
Plan that may be interpreted to the contrary, the Measurement Funds are to be
used for measurement

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purposes only, and a Participant's election of any such Measurement Fund, the
allocation to his or her Account thereto, the calculation of additional amounts
and the crediting or debiting of such amounts to a Participant's Account shall
not be considered or construed in any manner as an actual investment of his or
her Account in any such Measurement Fund.

          (f) Responsibility for Elections.  Neither the Company nor the
              ----------------------------
Committee shall have any liability as a result of, or be in any manner
responsible for, a Participant's individual deemed investment election or a
Participant's failure to make a deemed investment election, the Committee's only
duty being to credit the Participants' Accounts in accordance with the
Participants' deemed investment elections.  To the extent that no deemed
investment election is in effect, the Committee shall credit such Participant's
Account as if such Participant's deemed investment election were a money market
mutual fund or other similar short-term fixed-income fund selected by the
Committee.  The Committee may impose blackout periods from time to time to
facilitate introduction of new Measurement Funds or to change the administrative
delegate.

          (g) Change in Method.  Notwithstanding the foregoing, the Committee
              ----------------
may change the method of crediting earnings or losses to Accounts under the
Plan, by written notice to each Participant, which notice shall specify the new
method for crediting earnings or losses to be used and the effective date for
such change.

     5.  Vesting.
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          (a) A Participant shall become fully vested in the full value of the
amount credited to his or her Account upon attainment of age 55, death,
Disability, completion of at least five Years of Service or a Change in Control.

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          (b) A Participant whose employment with the Company or any Affiliated
Entity terminates prior to attainment of age 55 (for any reason other than death
or Disability) with fewer than five Years of Service will forfeit all amounts in
his or her Account upon his or her termination of employment.

          (c) Notwithstanding anything in this Section 5 to the contrary, a
Participant shall always be fully vested in and have a nonforfeitable right in
the full value of the amount credited to his or her Account under Section 3(c)
relating to the TSSL Special Pension Supplement.

     6.  Timing of Distribution.  Upon initial enrollment in the Plan, a
         ----------------------
Participant shall irrevocably elect on a form prescribed by the Company to
commence distribution of his or her vested Account balance either (a) upon his
or her Retirement or other termination of employment, or (b) in any calendar
year that is at least five years from initial participation in the Plan as may
be selected by the Participant, but not later than the year in which the
Participant attains age 70 (the "Distribution Year").  If no election is made,
the distribution will commence upon the Participant's termination of employment.

     7.  Method of Distribution.
         ----------------------

          (a) Upon initial enrollment in the Plan, a Participant shall
irrevocably elect on a form prescribed by the Company to receive his or her
vested Account balance pursuant to one of the following payment options:

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          (i) A single lump sum to be paid within 60 days following the quarter
in which the Participant Retires or otherwise terminates his or her employment
with the Company or an Affiliated Entity or within the first 60 days of the
Distribution Year.

          (ii) Annual installments, in an amount determined in accordance with
Section 7(c), over a period not to exceed 15 years, beginning no later than 60
days of the calendar year next following the year in which the Participant
Retires or otherwise terminates his or her employment with the Company or an
Affiliated Entity or March 1 of the Distribution Year.

     If no election is made, the distribution will be made in a lump sum
pursuant to (i) above.

          (b) All amounts credited to each Participant's Account which become
payable hereunder shall be paid by the Company or an Affiliated Entity in cash.
Each such Account shall be charged with the amount distributed with respect
thereto as of the date of payment.  The value of a Participant's Account shall
be determined as of the end of the [Quarter] preceding the payment to the
Participant.

          (c) In the event a benefit is paid in installments, each annual
installment payment amount shall be determined in the following manner:

               (i) the value of the Participant's Account balance as of the end
of the Quarter preceding the payment, divided by

               (ii) the total number of installment payments not yet made.

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     8.  Payments Upon Death.
         -------------------

          (a) In the event of a Participant's death prior to his or her
termination of employment with the Company or an Affiliated Entity, the value of
the amount credited to the Participant's Account as determined under Section 7
shall be paid to the Participant's Beneficiary in a single lump sum as soon as
practicable after such Participant's death.

          (b) In the event of a Participant's death after his or her termination
of employment but before full distribution of the amounts to be paid to him or
her pursuant to Section 7 has been completed, the value of the amounts payable
under Section 7 shall be paid to the Participant's Beneficiary in a single lump
sum as soon as is practicable after such Participant's death.

          (c) Each Participant may designate, from time to time, a Beneficiary
or Beneficiaries (who may be named contingently or successively) to whom any
amounts which remain credited to the Participant's Account at the time of his or
her death shall be paid.  Each such designation shall revoke all prior
designations by the same Participant, except to the extent otherwise
specifically noted, shall be in a form prescribed by the Company and shall be
effective only when filed by the Participant in writing with, and acknowledged
by, the Company during his or her lifetime.

     9.  No Funding Required.
         -------------------

          (a) Nothing in this Plan will be construed to create a trust or to
obligate the Company or any other person to segregate a fund, purchase an
insurance contract, or in any other way to fund currently the future payment of
any benefits hereunder, nor will anything herein be construed to give any
Participant or any other person rights to any specific assets of the Company

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or of any other person. Except as described in (b) below, any benefits which
become payable hereunder shall be paid from the general assets of the Company.

          (b) The Company in its sole discretion may establish a grantor or
other trust of which the Company is treated as the owner under the Code, to
provide for the payment of benefits hereunder, subject to the claims of the
Company's general creditors in the event of insolvency, and subject to such
other terms and conditions as the Company may deem necessary or advisable to
ensure (i) that benefits are not includible, by reason of the establishment or
funding of such trust, in the income of trust beneficiaries prior to actual
distribution and (ii) that the existence of such trust does not cause the Plan
or any other arrangement to be considered funded for purposes of Title I of
ERISA.

     10.  Plan Administration and Interpretation.  The Company shall have
          --------------------------------------
complete control over the administration of the Plan and complete control and
authority to determine, in its sole discretion, the rights and benefits and all
claims, demands and actions arising out of the provisions of the Plan of any
Participant, Beneficiary, or other person having or claiming to have any
interest under the Plan and the Company's determinations shall be conclusive and
binding on all such parties.  The Company shall be deemed to be the Plan
Administrator with the responsibility for complying with any reporting and
disclosure requirements of ERISA.  The power of the Company hereunder shall be
exercised by the Tyco Retirement Committee.  To the extent that the Committee is
unable or unwilling to exercise any right hereunder or make any determination
hereunder, however, the Board of Directors shall exercise such right or make
such determination.

     11.  Claims Procedure.
          ----------------

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          (a) Any Participant or Beneficiary of a deceased Participant (such
Participant or Beneficiary being referred to below as a "Claimant") may deliver
to the Committee a written claim for a determination with respect to the amounts
distributable to such Claimant from the Plan.  If such a claim relates to the
contents of a notice received by the Claimant, the claim must be made within 60
days after such notice was received by the Claimant.  All other claims must be
made within 180 days of the date on which the event that caused the claim to
arise occurred.  The claim must state with particularity the determination
desired by the Claimant.

          (b) The Committee shall consider a Claimant's claim within 90 days,
and shall notify the Claimant in writing:

               (i) that the Claimant's requested determination has been made,
and that the claim has been allowed in full; or

          (ii) that the Committee has reached a conclusion contrary, in whole or
in part, to the Claimant's requested determination, and such notice must set
forth in a manner calculated to be understood by the Claimant:

                    (A) the specific reason(s) for the denial of the claim, or
any part of it;

                    (B) specific reference(s) to pertinent provisions of the
Plan upon which such denial was based;

          (C) a description of any additional material or information necessary
for the Claimant to perfect the claim, and an explanation of why such material
or information is necessary; and

                                       15
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                    (D) an explanation of the claim review procedure set forth
in this Section 11.

          (c) Within 60 days after receiving a notice from the Committee that a
claim has been denied, in whole or in part, a Claimant (or the Claimant's duly
authorized representative) may file with the Committee a written request for a
review of the denial of the claim.  Thereafter, but not later than 30 days after
the review procedure began, the Claimant (or the Claimant's duly authorized
representative):

               (i) may review pertinent documents;

               (ii) may submit written comments or other documents; and/or

               (iii)  may request a hearing, which the Committee, in its sole
discretion, may grant.

          (d) The Committee shall render its decision on review promptly, and
not later than 60 days after the filing of a written request for review of the
denial, unless a hearing is held or other special circumstances require
additional time, in which case the Committee's decision must be rendered within
120 days after such date.  Such decision must be written in a manner calculated
to be understood by the Claimant, and it must contain:

               (i) specific reasons for the decision;

               (ii) specific reference(s) to the pertinent Plan provisions upon
which the decision was based; and

               (iii)  such other matters as the Committee deems relevant.

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<PAGE>

          (e) A Claimant's compliance with the foregoing provisions of this
Section 11 is a mandatory prerequisite to a Claimant's right to commence any
legal action with respect to any claim for benefits under this Plan.

     12.  Non-Assignable.  Amounts payable under this Plan shall not be subject
          --------------
to alienation, assignment, garnishment, execution or levy of any kind, and any
attempt to cause any such amount to be so subjected shall be null, void and of
no effect and shall not be recognized by the Company.

     13.  Termination and Modification.  The Company may, by action of the
          ----------------------------
Committee, terminate, suspend or amend this Plan at any time.  Notwithstanding
the foregoing, without the consent of the Participant, no such termination,
suspension or amendment shall cause the amount credited to such Participant's
Account to be less than the amount credited to such Participant's Account
immediately prior to such termination, suspension or amendment.

     14.  Parties.  The terms of this Plan shall be binding upon the Company,
          -------
its successors or assigns and each Participant participating herein and his or
her spouse, Beneficiaries, heirs, executors and administrators.

     15.  Liability of Company.  Subject to its obligation to pay the amount
          --------------------
credited to the Participant's Account at the time distribution is called for by
this Plan, neither the Company nor any person acting on behalf of the Company
shall be liable to any Participant or any other person for any act performed or
the failure to perform any act with respect to the Plan.

     16.  Notices.  Notices, elections or designations by a Participant to the
          -------
Company hereunder shall be addressed to the Committee.


                                       17
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Notices by the Company to a Participant shall be addressed to the Participant at
his or her most recent home address as reflected in the records of the Company.

     17.  Withholding.  All payments under this Plan shall be net of tax
          -----------
withholding required by applicable Federal and state laws.

     18.  Unsecured General Creditors.  No Participant or his or her legal
          ---------------------------
representative or any Beneficiary designated by him or her shall have any right,
other than the right of an unsecured general creditor, against the Company in
respect of the Account of such Participant established hereunder.

     19.  Effective Date.  This Plan shall be effective as of  October 1, 2000
          --------------
2000, and shall continue in existence thereafter until terminated pursuant to
Section 13.

     20.  Governing Law.  This Plan shall be construed and enforced in
          -------------
accordance with, and governed by, the laws of [the State of New Jersey].

     IN WITNESS WHEREOF, this restated and amended Plan has been duly signed for
and on behalf of the Company on the      day of     , 2000.

                                    TYCOM LTD.


                                    By:
                                       -----------------------------

                                       18
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                                  Appendix A
                                  ----------

                      Measurement Funds at  July 1, 2000
                      ----------------------------------


          Bond Fund of America;

          Fidelity Growth Company Fund;

          Fidelity Puritan Fund;

          Franklin Small Cap Growth Fund I;

          Future Measurement funds;

          Interest Income Fund;

          Neuberger & Berman Guardian Trust;

          PIMCO Capital Appreciation Fund;

          Spartan U.S. Equity Index Fund;

          Templeton Foreign Fund A; and

          Vanguard Windsor - II Fund

     Measurement funds will be deleted or added from time to time to reflect any
changes made in the investment funds for the Savings Plan; provided, however,
that none of the Fidelity Freedom Funds, any TyCom Stock Fund or any other fund
designated as a non-core fund under the Savings Plan will be a Measurement Fund.

                                       19