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                                                                   EXHIBIT 10.23


                         TERMINATION AGREEMENT, WAIVER,
                                       AND
                                 GENERAL RELEASE

      This Termination Agreement, Waiver, and General Release (the "Release") is
entered into this ____ day of January, 2002 (the "Effective Date") by and
between Nextera Enterprises, Inc., a Delaware corporation (the "Company"),
Sibson & Company LLC, a Delaware limited liability company ("Sibson") , and
Vincent C. Perro ("Employee") and is made with reference to the following:

                                    RECITALS

      A. The Company and Employee entered into that certain Employment Agreement
dated September 30, 2000 (the "Employment Agreement").

      B. Sibson is a wholly owned subsidiary of Nextera.

      C. On or about the Effective Date, Sibson sold all of its assets to The
Segal Group Inc. ("Segal") pursuant to that certain Asset Purchase Agreement by
and among The Segal Group, Inc., as Buyer, and Nextera Enterprises, Inc and
Sibson & Company LLC, as Sellers (the "Asset Purchase Agreement").

      D. As part of the sale to Segal, Segal intends to employ Employee and
Employee intends to accept such employment from Segal.

      E. Employee and the Company have agreed to terminate the Employment
Agreement as of the Effective Date so that Employee may accept employment with
Segal.

      NOW, THEREFORE, the parties agree as follows:

      1. Termination of Employment. The Company and Employee acknowledge and
agree that Employee's employment with the Company terminated on the Effective
Date. Employee shall receive his base compensation and his normal benefits shall
be paid to the Effective Date. The Company and Employee acknowledge that
Employee voluntarily resigned from his employment with the Company and both
parties agree that all references to Employee's termination shall state that
Employee voluntarily resigned.

      2. Benefits. Other than medical and dental benefits which Employee may
choose to continue at his expense pursuant to COBRA and conversion rights with
respect to life insurance and long-term disability insurance which Employee may
choose to convert at his expense, Employee's eligibility to participate in the
Company's benefits and benefit programs, including, but not limited to, the
post-retirement health care benefits, shall cease on the date that Segal makes
its benefits and benefit plans available to Employee, but in no case later than
the beginning of the third payroll period of Segal following the closing of the
transactions contemplated by the Asset Purchase Agreement.

      3. Accrued Vacation/Expenses. Within two (2) business days of the
Effective Date, Employee shall be paid, by wire transfer or direct deposit, less
applicable withholding taxes, for all accrued but unused vacation days to which
Employee is entitled subject to a maximum of five (5) days carry forward from
2001, and within fifteen (15) days of the Effective Date shall be reimbursed, by
wire transfer or direct deposit, for all unreimbursed expenses, pursuant to the
usual rules and procedures of the Company.


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      4. Profit Sharing Plan Contribution. The Company shall contribute $30,000
to the Company's qualified profit sharing plan in which Employee is a
participant as its contribution with respect to 2001 for Employee, no later than
April 10, 2002. In addition, the Company shall contribute $82.20 to the
Company's qualified profit sharing plan with respect to each day in the period
from January 1, 2002 to the Effective Date, for Employee, no later than April
10, 2002.

      5. Stock Options. The post-termination exercise period with respect to
options to purchase Nextera Class A common stock granted to Employee and which
are vested as of the Effective Date shall be extended to the first anniversary
date of the Effective Date, and any such options not exercised by such date
shall terminate on such date.

      6. February, 2001 Grant. Forty Thousand (40,000) of the One Hundred
Thousand (100,000) options to purchase Nextera Class A common stock granted to
Employee in February, 2001, shall vest on the Effective Date and the
post-termination exercise period with respect to such 40,000 options shall be
extended to the first anniversary of the Effective Date, and any such options
not exercised by such date shall terminate on such date.

      7. October, 2000 Grant. One Hundred Thousand (100,000) of the Four Hundred
Thousand (400,000) options to purchase Nextera Class A common stock granted to
Employee in October, 2000, shall vest on the Effective Date, and the
post-termination exercise period with respect to such 100,000 options shall be
extended to the first anniversary of the Effective Date, and any such options
not exercised by such date shall terminate on such date.

      8. Bonus. Employee shall be paid a bonus for the 2001 performance year in
the amount of $225,000 (the "Targeted Bonus"), less applicable withholding
taxes, by wire transfer or direct deposit, no later than April 10, 2002;
provided, however that if the payout under the Special Management Incentive is
greater than the Targeted Bonus, the Special Management Incentive shall be paid
instead, with $225,000 thereof payable as aforesaid no later than April 10, 2002
and the balance payable as aforesaid (subject to the provisions of the next
sentence) pursuant to the terms of the Special Management Incentive agreement.
If the Special Management Incentive is met, ten percent of the cash amount in
excess of $225,000, that would be paid to Employee if not for this sentence,
shall instead be contributed by Nextera or Sibson, on the same day that the
remainder of the excess is paid to Employee, into the Sibson Annual Incentive
Plan to be distributed as determined by Employee.

      9. Restricted Stock. Employee shall be vested in the 57,732 shares of
Nextera Class A common stock granted to Employee as a restricted stock purchase
award on May 3, 2001 and Nextera hereby releases Employee from Nextera's option
to repurchase such shares.

      10. Performance Award. The Company shall pay $47,600, less applicable
withholding taxes, by wire transfer or direct deposit, to Employee no later than
February, 8, 2002, which shall constitute payment in full of the Net Performance
Award (representing the right to deferred compensation in connection with the
restricted stock purchase award referred to in Section 9) granted to Employee on
May 3, 2001.

      11. No Other Termination Benefits. Notwithstanding any provision in the
Employment Agreement to the contrary, except as specifically set forth in
Section 2 above, Employee hereby waives all rights to all the termination
benefits set forth in the Employment Agreement and releases the Company and
Nextera from such obligations.

      12. Release of Company.

            (a) For good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, Employee does hereby unconditionally release
and forever discharge the Company, Nextera, and their divisions, subsidiaries,
and affiliates, and each of their respective shareholders,


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members, managers, officers, directors, partners, attorneys, employees, agents,
successors, and assigns, and each of them, as an individual and in every other
capacity, and all persons and entities acting by, through, under or in concert
with any of them, (collectively, the "Releasees"), from any and all charges,
complaints, claims, liabilities, obligations, promises, agreements, bonuses,
severance, benefits, contracts, commitments, controversies, damages, actions,
causes of action, suits, rights, demands, costs, losses, debts, penalties and
expenses of every nature whatsoever, known or unknown, suspected or unsuspected,
including, but not limited to, claims growing out of any legal restrictions on
the Company's right to terminate or take other actions against its employees
and/or claims under any other statutory, constitutional, regulatory or common
law right including, without limitation, any claims based on or arising under
the Human Rights laws of the State and City of New York ("Claims"), which
Employee now has, owns or holds, or claims to have, own or hold, or which
Employee at any time hereinafter may have, own or hold, or claim to have, own or
hold against any of the Releasees by reason of any and all matters arising out
of or resulting from or relating in any way to any acts or events occurring on
or before the date Employee signs this Release, including, but not limited to,
any and all Claims arising out of the Employment Agreement, his employment
relationship with the Company, and/or severance of the employment relationship.

            (b) Notwithstanding the provisions of Section 12(a) above, Employee
does not waive or release any right or claim he may have (i) pursuant to this
Agreement or (ii) pursuant to the Binding Term Sheet among the Company,
Employee, and other executive employees of the Company with respect to Special
Management Incentives.

            (c) In the event that the Company fails to make any payment to
Employee required to be made hereunder on the date such payment is required to
be made, the Company shall pay interest to Employee on the amount of any overdue
payment at the rate of 10% per annum.

      13. Release of Employee.

    (a) For good and valuable consideration, the receipt and sufficiency of
    which is hereby acknowledged, and except as set forth in Section 13.(b)
    below, the Company, on behalf of the Company and its parents, affiliates,
    subsidiaries, successors, and assigns, and all other "Releasees" (as that
    terms is defined in Section 12 above), hereby releases and forever
    discharges the Employee and the Employee's executors, heirs, and assigns
    from all claims, charges, or demands, in law or in equity, whether known or
    unknown, which may have existed or which may now exist from the beginning of
    time to the date of this release, including, without limitation, any claim
    arising from or related to the Employee's employment or termination from
    employment with the Company or the Employee's status as a director, officer,
    or fiduciary with respect to the Company or its affiliates or subsidiaries,
    or with respect to any of its or their employee pension benefit or welfare
    benefit plans and, provided that Employee has entered into a written
    employment contract with a term extending to December 31, 2002 or later with
    Segal on or before the date of this release, then this release shall include
    a release of any claims that the Company or its parents, affiliates,
    successors, or assigns may have under that certain Non-Compete,
    Non-Solicitation, Proprietary Information, Confidentiality and Inventions
    Agreement between the Employee and Nextera Enterprises, L.L.C. (as
    predecessor to Nextera) dated as of August 31, 1998.

            (b) Notwithstanding the provisions of Section 13.(a) above, Employee
shall not be released from any claims, charges, or demands, as set forth in
Section 13.(a) above, arising from or due to any fraudulent, grossly negligent,
or criminal act by the Employee.

      14. Indemnification. If Employee is made a party or is threatened to be
made a party to any Proceeding (as defined below) by reason of the fact that he
is or was an officer, managing director, employee, agent, manager, trustee,
consultant, or representative of the Company or any of the Releasees or is or
was serving at the request of the Company or any of the Releasees, or in
conjunction with his

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employment by the Company, as a director, officer, member, employee, agent,
manager, trustee, consultant, or representative of another Person (as defined
below), or if any Claim (as defined below) is made or is threatened to be made
that arises out of or relates to Employee's service in any of the foregoing
capacities, then Employee shall promptly be indemnified and held harmless to the
fullest extent permitted or authorized by the Certificate of Incorporation or
Bylaws of the Company, or if greater, by applicable law, against any and all
costs, expenses, liabilities, and losses (including, without limitation,
attorneys' and other professional fees and charges, judgments, interest,
expenses of investigation, penalties, fines, ERISA excise taxes or penalties and
amounts paid or to be paid in settlement) incurred or suffered by Employee in
connection therewith or in connection with seeking to enforce his rights under
this Section 14, and such indemnification shall continue as to Employee even if
he has ceased to be an officer, member, employee, agent, manager, trustee,
consultant, or representative of the Company or other Person and shall inure to
the benefit of Employee's heirs, executors, and administrators. Employee shall
be entitled to prompt advancement of any and all costs and expenses (including,
without limitation, attorneys' and other professional fees and charges) incurred
by him in connection with any such Proceeding or Claim, or in connection with
seeking to enforce his rights under this Section 14, any such advancement to be
made within 15 days after he gives written notice, supported by reasonable
documentation, requesting such advancement. Such notice shall include, to the
extent required by applicable law, an undertaking by Employee to repay the
amount advanced, on an after-tax basis (that is, net of any applicable taxes),
if he is ultimately determined not to be entitled to indemnification against
such costs and expenses. Nothing in this Agreement shall operate to limit or
extinguish any right to indemnification, advancement of expenses, or
contribution that Employee would otherwise have (including, without limitation,
by agreement or under applicable law). For purposes of this Agreement, "Claim"
shall mean any claim, demand, request, investigation, dispute, controversy,
threat, discovery request, or request for testimony or information, except for
those arising from or due to any fraudulent, grossly negligent, or criminal act
by the Employee. "Person" shall mean any individual, corporation, partnership,
limited liability company, joint venture, trust, estate, board, committee,
agency, body, employee benefit plan, or other person or entity. "Proceeding"
shall mean any actual or threatened action, suit, or proceeding, whether civil,
administrative, investigative, appellate, formal, informal, or other, except for
those arising from or due to any fraudulent, grossly negligent, or criminal act
by the Employee.

      15. No Claims Filed; Reservation of Rights. Employee represents that he
has not previously filed, and will not hereafter file, any lawsuits or any
charges, complaints, petitions, or other accusatory pleadings against any of the
Releasees in any court, with any governmental agency, or in any other forum
based upon, arising out of or related in any way to Employee's employment with
or severance of employment with the Company. Anything in this Agreement to the
contrary notwithstanding, the Employee shall retain and shall be entitled to
enforce, all rights arising under or with respect to: (i) the existing
obligation, if any, of the Company, its parents or affiliates to indemnify and
hold harmless the Employee whether pursuant to the provisions of the certificate
of incorporation or by-laws of the Company, its parents, or affiliates, or the
terms of its or their employee pension benefit or welfare benefit plans; (ii)
any and all directors and officers or fiduciaries liability insurance coverage
applicable to the Employee; (iii) any and all benefits under the employee
pension benefit plans of the Company, its parents, or affiliates to which the
Employee, as a terminated employee, is or shall be entitled in accordance with
the terms thereof; (iv) federal and state securities laws; and (v) the matters
described in Section 12(b) hereof; provided, however, that in no case shall
Employee have any rights under the Company's post-retirement health care benefit
plan.

      16. Directors and Officers Insurance. The Company agrees that it will
maintain directors' and officers' liability insurance covering the actions of
its past directors and officers, including Employee.

      17. Press Release. Sibson's/Nextera's press release announcing the sale to
Segal will mention that Employee, currently COO of Nextera, will be resigning to
head Sibson Consulting within The Segal Group. Subject to Segal's consent and
approval, Segal's press release announcing the purchase shall contain a quote
from Employee as follows: "We are delighted to be joining with Segal to develop
our joint capabilities for providing high impact consulting in what we expect
will be the fastest growing sector of

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the consulting industry."

      18. Proxy Reporting. The proxy statement to be filed with the SEC in
conjunction with the Company's next stockholders meeting shall explicitly state:
(i) that Employee voluntarily resigned to join the business of Sibson which was
sold to Segal; (ii) what Employee's role will be with Segal; and (iii) if, and
to the extent the Special Management Incentive is met, that a portion of the
Special Management Incentive was transferred to the Sibson bonus pool. The
language in the proxy statement shall conform with the language of this Release
except for SEC requirements that may arise. Employee shall have the right to
review the portion of the proxy statement relevant to him and to his
compensation disclosures prior to filing and Employee shall have the right to
enforce his rights under this Release.

      19. No Inducement. Employee acknowledges that there have been no
representations of any kind or character which have been made to him by the
Releasees to induce him to execute this Agreement.

      20. Tax Issues. Neither the Company nor Sibson has made any representation
to Employee as to the income or excise tax effects of the provisions of this
Release. Employee shall look solely to his own tax advisors as to the income and
excise tax effects of the provisions of this Release.

      21. Governing Law. This Release will be construed under, and interpreted
in accordance with, the laws of the state where Employee performed substantially
all of his duties for the Company as they exist on the date this Release is
executed, without giving effect to the choice or conflicts of laws provisions
thereof. This Release will be binding upon and inure to the benefit of, and be
enforceable by, the parties hereto and their respective successors and assigns.

      22. Entire Agreement. This Release sets forth the entire agreement and
understanding between the parties relating to the subject matter hereof and
supersedes any and all prior agreements, understandings, negotiations, and
discussions, whether oral or written, of the parties. This Release may not be
amended except by an instrument in writing signed on behalf of each of the
parties hereto. No amendment, supplement, modification, or waiver of this
Release shall be binding unless executed in writing by the party to be bound
thereby.

      23. Multiple Counterparts. This Release may be executed in one or more
counterparts, and by facsimile, each of which shall be deemed an original, but
all of which together shall constitute one and the same instrument.

                         [REMAINDER OF PAGE LEFT BLANK]

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            We, the undersigned, hereby certify that we have read this entire
Release and have had the terms used herein and the consequences thereof
explained by our respective attorneys. We fully understand all the terms and
consequences of this Release and, based on such, execute and deliver it.

                                /s/ Vincent C. Perro
                             ---------------------------------------------
                             Vincent C. Perro


                             Sibson & Company LLC, a Delaware limited liability
                              company


                             By:  /s/ Michael P. Muldowney
                                -------------------------------------------
                                  Name: Michael P. Muldowney
                                  Its:  Secretary


                             Nextera Enterprises, Inc. a Delaware corporation


                             By:  /s/ Michael P. Muldowney
                                -------------------------------------------
                                  Name: Michael P. Muldowney
                                  Its: CFO