<PAGE>
                                                                     EXHIBIT 4.2

NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. NO SALE, TRANSFER
OR OTHER DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (I)
AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO, OR (II) AN OPINION OF
COUNSEL, REASONABLY SATISFACTORY TO COUNSEL TO THE COMPANY, THAT AN EXEMPTION
FROM REGISTRATION UNDER SAID ACT IS AVAILABLE.

<TABLE>
<S>                 <C>                                                     <C>
December 31, 2002      AMENDED AND RESTATED STOCK PURCHASE WARRANT          Warrant No.: 7
                    To Subscribe for and Purchase Class A Common Stock of
</TABLE>

                            NEXTERA ENTERPRISES, INC.

         THIS AMENDED AND RESTATED STOCK PURCHASE WARRANT ("Warrant") certifies
that, for value received, Bank of America, N.A. (together with any subsequent
transferees of all or any portion of this Warrant, the "Holder"), is entitled,
upon the terms and subject to the conditions hereinafter set forth, to subscribe
for and purchase from Nextera Enterprises, Inc., a Delaware corporation
(hereinafter called the "Company"), up to seven hundred seventy-three thousand,
six hundred and forty-six (773,646) fully paid and non-assessable shares of the
Company's Class A Common Stock, $0.001 par value per share (the "Shares"), at
the price equal to the Exercise Price (as defined in Section 1 hereof) (subject
to adjustment as provided in Section 7 hereof). The number and character of such
Shares are subject to adjustment as provided herein. Capitalized terms used
herein and not defined herein shall have the meanings given such terms in that
certain Second Amended and Restated Credit Agreement dated December 31, 2002, by
and among the Company, the Holder and the other lenders party thereto (the
"Credit Agreement"; and together with all related promissory notes, mortgages,
guaranties, agreements, documents and instruments from time to time entered into
by Company and any other person or obligor pursuant thereto, the "Credit
Documents").

         This Warrant amends and restates in its entirety that certain Warrant
for up to seven hundred seventy-three thousand, six hundred and forty-six
(773,646) fully paid and non-assessable shares of the Company's Class A Common
Stock, $0.001 par value per share issued on March 29, 2002 (the "Prior Warrant")
made by the Company in favor of the Holder.

         1.       Definitions. As used herein the following terms shall have the
                  following meanings:

                  "Act" means the Securities Act of 1933 as amended, or a
                  similar Federal statute and the rules and regulations of the
                  Commission issued under that Act, as they each may, from time
                  to time, be in effect.

                  "Additional Shares of Common Stock" shall mean all shares of
                  Common Stock issued (or, pursuant to Section 7(c), deemed to
                  be issued) by the Company after the Original Issue Date, but
                  shall not include:

                  (A)      shares of Common Stock issued or issuable upon
                  conversion of shares of all of preferred stock of the Company
                  outstanding as of the Original Issue Date;

                  (B)      shares of Common Stock issued or issuable upon
                  exercise of this Warrant or any other warrant or option of the
                  Company outstanding as of the Original Issue Date;
<PAGE>
                  (C)      shares of Common Stock issued by way of dividend or
                  other distribution on shares of Common Stock excluded from the
                  definition of Additional Shares of Common Stock by the
                  foregoing clause (A) or (B) or on Common Stock so excluded; or

                  (D)      shares issued under an employee stock purchase plan
                  or pursuant to options exercisable for shares of Common Stock
                  (such number subject to equitable adjustment in the event of
                  any stock dividend, stock split, combination, reorganization,
                  recapitalization, reclassification or other similar event),
                  issued after the date of this Warrant to directors, officers,
                  employees or consultants of the Company and any Subsidiary
                  pursuant to any qualified or non-qualified stock option plan
                  or other equity incentive plan approved by the Board of
                  Directors of the Company, equal to the first 30% of the
                  outstanding stock of the Company, calculated on a
                  post-Original Issue Date, fully-diluted basis.

                  "Common Stock" shall mean the Class A Common Stock of the
                  Company, $0.001 par value per share.

                  "Convertible Securities" shall mean any evidences of
                  indebtedness, shares or other securities directly or
                  indirectly convertible into or exchangeable for Common Stock.

                  "Exercise Price" shall mean $0.86 per share.

                  "New Financing Source" shall mean a source other than the
                  Company.

                  "Option" shall mean rights, options or warrants to subscribe
                  for, purchase or otherwise acquire Common Stock or Convertible
                  Securities.

                  "Original Issue Date" shall mean the date on which this
                  Warrant is originally issued.

         2.       Purchase Rights. The purchase rights represented by this
Warrant are exercisable by the Holder in whole or in part (and not as to a
fractional share), at any time and from time to time commencing on the date
hereof and ending at 5:00 p.m. on the date (the "Expiration Date") eighteen (18)
months after the indefeasible payment in full in cash or cash equivalents of the
Credit Obligations.

         3.       Exercise of Warrant; Net Issue Exercise.

         3.1      Exercise of Warrant. Subject to Section 2 above, the purchase
rights represented by this Warrant may be exercised, in whole or in part and
from time to time, by the surrender of this Warrant and the duly executed Notice
of Exercise (the form of which is attached as Exhibit A) at the principal office
of the Company and by the payment to the Company, by check, of an amount equal
to the then applicable Exercise Price per share multiplied by the number of
Shares then being purchased. Upon exercise, the Holder shall be entitled to
receive, within a reasonable time, a certificate or certificates, issued in the
Holder's name or in such name or names as the Holder may direct, for the number
of Shares so purchased. The Shares so purchased shall be deemed to be issued as
of the close of business on the date on which this Warrant shall have been
exercised.

         3.2.     Net Issue Exercise.

                  (a)      In lieu of exercising this Warrant as set forth in
         Section 3.1, the Holder may elect to receive Shares equal to the value
         of this Warrant (or the portion thereof being cancelled) by surrender
         of this Warrant at the principal office of the Company together with
         notice of such election in which event the Company shall issue to the
         Holder a number of Shares computed using the following formula:

                                  X = Y (A - B)
                                      ---------
                                           A


                                       2
<PAGE>
Where X =       the number of Shares to be issued to the Holder;

                  Y = the number of Shares purchasable under this Warrant, or if
                  only a portion of this Warrant is being cancelled, the gross
                  number of Shares covered by the portion of this Warrant being
                  cancelled;

         A =      the fair market value of one Share, as determined by the Board
                  of Directors of the Company pursuant to paragraph (b) below,
                  as at the time the net issue election is made pursuant to this
                  Section (the "Determination Date"); and

         B =      the Exercise Price (as adjusted to the date of such
                  calculations).

Such Shares shall be issued as soon as practicable after the Determination Date.

                  (b)      For purposes of this Section, fair market value of a
Share shall be determined as follows:

                                    (A) If the Company's Common Stock is not
                           publicly traded at the Determination Date, the fair
                           market value of a Share shall be a value reasonably
                           determined by the Company's Board of Directors. In
                           the event that the Holder disagrees with the Board of
                           Directors' determination of fair market value, then
                           the fair market value shall be determined by an
                           appraiser selected by the Holder (the "Holder's
                           Appraiser") and whose appraisal (the "Holder's
                           Appraisal") shall be furnished to the Company within
                           20 days after the Board of Directors' determination
                           of fair value, and if the Company does not object to
                           such determination within 15 days after receipt of
                           the Holder's appraisal, then the fair market value
                           determined by the Holder's Appraiser shall be the
                           fair market value of a Share. In the event that the
                           Company objects to such determination then the
                           Company shall select an appraiser (the "Company's
                           Appraiser") who shall review the determination of the
                           Holder's Appraiser and issue a report thereon (the
                           "Company's Appraisal") within 30 days after the
                           delivery of the Holder's Appraisal to the Company and
                           within 10 days after the issuance of such report to
                           the Holder's Appraiser, the Holder's Appraiser and
                           the Company's Appraiser shall meet to negotiate in
                           good faith to reach agreement on the fair market
                           value of a Share, and such agreed value shall be the
                           fair market value of a Share. In the event that the
                           Company's Appraiser and the Holder's Appraiser are
                           unable to reach agreement then such Appraisers shall
                           select an appraiser (the "Third Appraiser") within 5
                           days after the meeting between the Holder's Appraiser
                           and the Company's Appraiser, and the average of two
                           appraisals, consisting of the appraisal made by the
                           Third Appraiser and the appraisal of the Holder's
                           Appraiser and Company's Appraiser (whichever is
                           closest to that of the Third Appraiser), shall be
                           conclusive and binding on the Company and the Holder.
                           The Company and the Holder shall each pay one half
                           (1/2) of the fees and expenses of each of the
                           Company's Appraiser, the Holder's Appraiser and the
                           Third Appraiser.

                                    (B) if the Company's Common Stock is
                           publicly traded on the Determination Date, the fair
                           market value of a Share shall be equal to (1) the
                           average of the closing prices quoted on the Nasdaq
                           Stock Exchange, Inc., if applicable, or the average
                           of the last bid and asked prices of the Common Stock
                           quoted in the Nasdaq OTC Bulletin Board or the
                           over-the-counter-market, or (2) if the Common Stock
                           is then traded on a national securities exchange, the
                           average of the high and low closing prices of the
                           Common Stock listed on the principal national
                           securities exchange on which the Common Stock is so
                           traded, in each case for the twenty (20) trading days
                           preceding the Determination Date.


                                       3
<PAGE>
         4.       Shares to be Issued; Reservation of Shares. The Company
covenants that the Shares that may be issued upon the exercise of the purchase
rights represented by this Warrant will, upon issuance, be fully paid and
non-assessable, and free from all liens and charges with respect to the issue
thereof. During the period within which the purchase rights represented by the
Warrant may be exercised, the Company will at all times have authorized and
reserved, for the purpose of issuance upon exercise of the purchase rights
represented by this Warrant, a sufficient number of shares of its Common Stock
to provide for the exercise of the right represented by this Warrant.

         5.       No Fractional Shares. No fractional shares shall be issued
upon the exercise of this Warrant. In lieu thereof, a cash payment shall be made
equal to such fraction multiplied by the fair market value of such shares of
Common Stock, as determined pursuant to Section 3.2(b) above.

         6.       Adjustment for Merger, Consolidation or Sale of Assets. In the
event that at any time or from time to time after the Original Issue Date, the
Company shall merge or consolidate with or into another entity or sell all or
substantially all of its assets, the Holder hereof shall thereafter have the
right to receive the kind and amount of shares of stock, other securities,
property or cash deliverable or payable to the holders of the Common Stock of
the Company that the Holder hereof upon exercise of this Warrant would have been
entitled to had the Holder hereof exercised the remaining portion of this
Warrant into shares of Common Stock immediately prior thereto.

         7.       Adjustment of Exercise Price and Number of Shares.

                  (a)      Adjustment of Exercise Price and Number of Shares.
         The Exercise Price and number of shares of Common Stock issuable upon
         the exercise of the Warrant shall be adjusted as set forth in this
         Section 7 with the intent that the rights of the Holder to exercise
         shall not be impaired.

                  (b)      Adjustment for Combination, Consolidation, Stock
         Dividend or Subdivision of Common Stock. If the outstanding shares of
         Common Stock shall be subdivided into a greater number of shares or a
         dividend in Common Stock shall be paid in respect of Common Stock, the
         Exercise Price in effect immediately prior to such subdivision or at
         the record date of such dividend shall simultaneously with the
         effectiveness of such subdivision or immediately after the record date
         of such dividend be proportionately reduced. If outstanding shares of
         Common Stock shall be combined or consolidated into a smaller number of
         shares, the Exercise Price in effect immediately prior to such
         combination or consolidation shall, simultaneously with the
         effectiveness of such combination or consolidation, be proportionately
         increased. When any adjustment is required to be made in the Exercise
         Price, the number of shares of Common Stock purchasable upon the
         exercise of this Warrant shall be changed to the number determined by
         dividing (i) an amount equal to the number of shares issuable upon the
         exercise of this Warrant immediately prior to such adjustment,
         multiplied by the Exercise Price in effect immediately prior to such
         adjustment, by (ii) the Exercise Price in effect immediately after such
         adjustment.

                  (c)      Issue of Options and Convertible Securities Deemed
         Issue of Additional Shares of Common Stock. If the Company at any time
         or from time to time after the Original Issue Date shall issue any
         Options or Convertible Securities or shall fix a record date for the
         determination of holders of any class of securities entitled to receive
         any such Options or Convertible Securities, then the maximum number of
         shares of Common Stock (as set forth in the instrument relating
         thereto, without regard to any provision contained therein for a
         subsequent adjustment of such number) issuable upon the exercise of
         such Options or, in the case of Convertible Securities or Options
         therefor, the conversion or exchange of such Convertible Securities,
         shall be deemed to be Additional Shares of Common Stock issued as of
         the time of such issue or, in case such a record date shall have been
         fixed, as of the close of business on such record date, provided that
         Additional Shares of Common Stock shall not be deemed to have been
         issued unless the consideration per share (determined pursuant to
         paragraph (e) below) of such Additional Shares of Common Stock would be
         less than the Exercise Price in effect on the date of and immediately


                                       4
<PAGE>
         prior to such issue, or such record date, as the case may be, and
         provided further in any such case in which Additional Shares of Common
         Stock are deemed to be issued:

                           (i)      No further adjustment in the Exercise Price
                  shall be made upon the subsequent issue of Convertible
                  Securities or shares of Common Stock upon the exercise of such
                  Options or conversion or exchange of such Convertible
                  Securities;

                           (ii)     If such Options or Convertible Securities by
                  their terms provide, with the passage of time or otherwise,
                  for any increase in the consideration payable to the Company,
                  or decrease in the number of shares of Common Stock issuable,
                  upon the exercise, conversion or exchange thereof, the
                  Exercise Price computed upon the original issue thereof (or
                  upon the occurrence of a record date with respect thereto),
                  and any subsequent adjustments based thereon, shall, upon any
                  such increase or decrease becoming effective, be recomputed to
                  reflect such increase or decrease insofar as it affects such
                  Options or the rights of conversion or exchange under such
                  Convertible Securities;

                           (iii)    No readjustment pursuant to clause (ii)
                  above shall have the effect of increasing the Exercise Price
                  to an amount which exceeds the lower of (A) the Exercise Price
                  immediately prior to the adjustment affected upon the original
                  issue of Options or Convertible Securities (or upon the
                  occurrence of a record date with respect thereto) pursuant to
                  the provisions hereof, or (B) the Exercise Price that would
                  have resulted from any issuance of Additional Shares of Common
                  Stock between the original adjustment date and such
                  readjustment date;

                           (iv)     Upon the expiration or termination of any
                  unexercised Option, the Exercise Price shall be readjusted to
                  the Exercise Price which would have been in effect at the time
                  of such expiration or termination had such Option never been
                  issued (but including the recalculation of any intervening
                  adjustments), and the Additional Shares of Common Stock deemed
                  issued as the result of the original issue of such Option
                  shall not be deemed issued for the purposes of any subsequent
                  adjustment of the Exercise Price; and

                           (v)      In the event of any change in the number of
                  shares of Common Stock issuable upon the exercise, conversion
                  or exchange of any Option or Convertible Security, including,
                  but not limited to, a change resulting from the antidilution
                  provisions thereof, the Exercise Price then in effect shall
                  forthwith be readjusted to such Exercise Price as would have
                  obtained had the adjustment which was made upon the issuance
                  of such Option or Convertible Security (prior to such change)
                  been made upon the basis of such change, but no further
                  adjustment shall be made for the actual issuance of Common
                  Stock upon the exercise or conversion of any such Option or
                  Convertible Security.

                  (d)      Adjustment of Exercise Price Upon Issuance of
         Additional Shares of Common Stock. In the event the Company shall at
         any time after the Original Issue Date issue Additional Shares of
         Common Stock (including Additional Shares of Common Stock deemed to be
         issued pursuant to paragraph (c) above), without consideration or for a
         consideration per share less than the Exercise Price in effect on the
         date of and immediately prior to such issue, then and in such event,
         such Exercise Price shall be reduced, concurrently with such issue, to
         a price (calculated to the nearest cent) calculated as follows:

                           (i)      The adjusted Exercise Price shall be equal
                  to a fraction: (A) the numerator of which shall be the number
                  of shares of Common Stock outstanding immediately prior to
                  such issue (including shares described in clause (ii) below),
                  plus the number of shares of Common Stock which the aggregate
                  consideration received by the Company for the total number of
                  Additional Shares of Common Stock so issued would


                                       5
<PAGE>
                  purchase at such Exercise Price; and (B) the denominator of
                  which shall be the number of shares of Common Stock
                  outstanding immediately prior to such issue (including shares
                  described in clause (ii) below) plus the number of such
                  Additional Shares of Common Stock so issued.

                           (ii)     For the purposes of clause (i), the number
                  of shares of Common Stock outstanding immediately prior to
                  such issue shall be calculated on a fully diluted basis, as if
                  all Convertible Securities had been fully converted into
                  shares of Common Stock immediately prior to such issuance and
                  the Warrant and any other outstanding Options had been fully
                  exercised immediately prior to such issuance (and any
                  resulting Convertible Securities fully converted into Common
                  Stock) as of such date.

                           (iii)    The applicable Exercise Price shall not be
                  reduced at the time of any issuance of Additional Shares of
                  Common Stock if the amount of such reduction would be an
                  amount less than $0.01, but any such amount shall be carried
                  forward and reduction with respect thereto shall be made at
                  the time and together with any subsequent reduction which,
                  together with such amount and any other amounts so carried
                  forward, shall aggregate $0.01 or more.

                  (e)      Determination of Consideration. For purposes of
         paragraph (d), the consideration received by the Company for the issue
         of any Additional Shares of Common Stock shall be computed as follows:

                           (i)      Cash and Property: Such consideration shall:

                                    (A)      insofar as it consists of cash, be
                           computed at the aggregate of cash received by the
                           Company;

                                    (B)      insofar as it consists of property
                           other than cash, be computed at the fair market value
                           thereof at the time of such issue, as determined in
                           good faith by the Board of Directors; and

                                    (C)      in the event Additional Shares of
                           Common Stock are issued together with other shares or
                           securities or other assets of the Company for
                           consideration which covers both, be the proportion of
                           such consideration so received, computed as provided
                           in clauses (A) and (B) above, as determined in good
                           faith by the Board of Directors.

                           (ii)     Options and Convertible Securities. The
                  consideration per share received by the Company for Additional
                  Shares of Common Stock deemed to have been issued pursuant to
                  paragraph (c), relating to Options and Convertible Securities,
                  shall be determined by dividing:

                                    (A)      the total amount, if any, received
                           or receivable by the Company as consideration for the
                           issue of such Options or Convertible Securities, plus
                           the minimum aggregate amount of additional
                           consideration (as set forth in the instruments
                           relating thereto, without regard to any provision
                           contained therein for a subsequent adjustment of such
                           consideration) payable to the Company upon the
                           exercise of such Options or the conversion or
                           exchange of such Convertible Securities, or in the
                           case of Options for Convertible Securities, the
                           exercise of such Options for Convertible Securities
                           and the conversion or exchange of such Convertible
                           Securities; by

                                    (B)      the maximum number of shares of
                           Common Stock (as set forth in the instrument relating
                           thereto, without regard to any provision contained


                                       6
<PAGE>
                           therein for a subsequent adjustment of such number)
                           issuable upon the exercise of such Options or the
                           conversion or exchange of such Convertible
                           Securities.

                  (f)      Certificate as to Adjustments. Upon the occurrence of
         each adjustment or readjustment of the Exercise Price pursuant to this
         Section 7, the Company at its expense shall promptly compute such
         adjustment or readjustment in accordance with the terms hereof and
         furnish to the Holder a certificate setting forth such adjustment or
         readjustment and showing in detail the facts upon which such adjustment
         or readjustment is based. The Company shall, upon the written request
         at any time of the Holder, furnish or cause to be furnished to such
         holder a like certificate setting forth (i) such adjustments and
         readjustments, (ii) the Exercise Price at the time in effect, and (iii)
         the number of shares of Common Stock and the amount, if any, of other
         property which at the time would be received upon the exercise of the
         Warrant.

         8.       No Rights as a Shareholder. This Warrant does not entitle the
Holder to any voting rights or other rights as a shareholder of the Company
prior to exercise of this Warrant and the payment for the Shares so purchased.
Notwithstanding the foregoing, the Company agrees to transmit to the Holder such
information, documents and reports as are generally distributed to holders of
the capital stock of the Company concurrently with the distribution thereof to
the shareholders. Upon valid exercise of this Warrant and payment for the Shares
so purchased in accordance with the terms of the Warrant, the Holder shall be
deemed a shareholder of the Company.

         9.       Sale or Transfer of the Warrant; Legend. The Warrant and the
Shares shall not be sold or transferred unless either (i) they first shall have
been registered under the Act, or (ii) the Company first shall have been
furnished with an opinion of legal counsel reasonably satisfactory to the
Company to the effect that such sale or transfer is exempt from the registration
requirements of the Act. Each certificate representing any Warrant shall bear
the legend set out on page 1 hereof. Each certificate representing any Shares
shall bear a legend substantially in the following form, as appropriate:

                  THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED
                  FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION WITH,
                  THE SALE OR DISTRIBUTION THEREOF. NO SUCH SALE OR DISPOSITION
                  MAY BE EFFECTED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT
                  RELATED THERETO OR AN OPINION OF COUNSEL REASONABLY
                  SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT
                  REQUIRED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.

Such Warrant and Shares may be subject to additional restrictions on transfer
imposed under applicable state and federal securities law.

         10.      Put Right. Commencing on December 31, 2004, and prior to the
Expiration Date, the Holder shall have the right, exercised by the delivery of
written notice to the Company (a "Put Notice"), to require the Company to cancel
the unexercised portion of this Warrant, and all related rights in exchange for
a cash payment (the "Put Payment") equal to $0.3525 per share payable to the
Holder within ten (10) days of receipt by the Company of the Put Notice and the
original Warrant for cancellation.

         11.      Call Option. At any time during the one year period following
the indefeasible payment in full in cash or cash equivalents of the Credit
Obligations, and prior to June 30, 2004, the Company shall have the right
exercised by the delivery of written notice to the Holder (a "Call Notice") to
cancel this Warrant and the purchase rights hereunder in exchange for a cash
payment (the "Call Payment") equal to $0.5288 per share, payable to the Holder
within five (5) days after delivery by the Company of the Call Notice, provided
however, that any payment made pursuant to this Section 11 may only be made out
of a New Financing Source. Notwithstanding anything to the contrary contained
herein, the Holder shall be entitled to exercise this Warrant in whole or in
part at any time after the receipt of the Call Notice until the receipt by the
Holder of the Call Payment. In the event that the Holder chooses to


                                       7
<PAGE>
exercise all or a portion of the Warrant after receipt of the Call Notice, the
Company shall have the option to rescind such Call Notice or to exercise its
call option with respect to that portion of the Warrant which remains
unexercised through the delivery of a pro rata portion of the Call Payment. The
Company shall have the right to exercise the call option set forth herein one
time only.

         12.      Modifications and Waivers. This Warrant may not be changed,
waived, discharged or terminated except by an instrument in writing signed by
the party against which enforcement of the same is sought.

         13.      Notices. Any notice, request or other document required or
permitted to be given or delivered to the Holder or the Company shall be
sufficiently given or made if sent by registered or certified mail, postage
prepaid, addressed to the parties as provided below:

                  If to Holder:     Bank of America, N.A.
                                    6610 Rockledge Drive, 6th Floor
                                    Bethesda, MD  20817
                                    Attn:   Michael R. Heredia,
                                            Managing Director

                  with a copy to:

                                    Brown, Rudnick, Freed & Gesmer
                                    One Financial Center
                                    Boston, MA  02111
                                    Attn:   William R. Baldiga, Esquire
                                            Mary D. Bucci, Esquire


                                       8
<PAGE>
                  If to Company:  Nextera Enterprises, Inc.
                                  4 Cambridge Center
                                  Cambridge, MA 02142
                                  Attn:  Michael P. Muldowney,
                                         Chief Financial Officer

                  with a copy to: Maron & Sandler
                                  844 Moraga Drive
                                  Los Angeles, CA  90049
                                  Attn:  Stanley E. Maron, Esquire

         14.      Loss, Theft, Destruction or Mutilation of Warrant. The Company
covenants with the Holder that upon its receipt of evidence reasonably
satisfactory to the Company of the loss, theft, destruction or mutilation of
this Warrant or any stock certificate and, in the case of any such loss, theft
or destruction, of an indemnity or security reasonably satisfactory to it, and
upon reimbursement to the Company of all reasonable expenses incidental thereto,
and upon surrender and cancellation of this Warrant or stock certificate, if
mutilated, the Company will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost, stolen, destroyed or mutilated Warrant or
stock certificate.

         15.      Representations and Warranties of Holder. By accepting this
Warrant, the Holder represents and warrants that it is acquiring this Warrant
and the Shares for its own account, for investment and not with a view to, or
for sale in connection with, any distribution thereof or any part thereof.
Holder represents and warrants that it is (a) experienced in the evaluation of
businesses similar to the Company, (b) is able to fend for itself in the
transactions contemplated by this Warrant, (c) has such knowledge and experience
in financial and business matters as to be capable of evaluating the merits and
risks of an investment in the Company, (d) has the ability to bear the economic
risks of an investment in the Company, (e) has been furnished with or has had
access to such information as is specified in subparagraph (b)(2) of Rule 502
promulgated under the Act and (f) has been afforded the opportunity to ask
questions of and to receive answers from the Company and to obtain any
additional information necessary to make an informed investment decision with
respect to an investment in the Company. The Holder further represents that it
is an "accredited investor" as defined in Rule 501(a) of Regulation D under the
Act.

         16.      Representations and Warranties of Company. The Company
represents that:

                           (a)      The execution and delivery of this Warrant
                  has been duly authorized by the Company's Board of Directors
                  and constitutes the legal, valid and binding obligation of the
                  Company enforceable against the Company in accordance with its
                  terms, except as enforcement thereof may be limited by
                  bankruptcy, insolvency, or other laws affecting the
                  enforcement of creditors' rights in general and except that
                  the enforceability of the obligations hereunder is subject to
                  general principals of equity (regardless of whether such
                  enforceability is considered in a proceeding at equity or at
                  law). Neither the execution nor the delivery of this Warrant,
                  nor fulfillment of nor compliance with the terms and
                  provisions of this Warrant, nor the issuance of Shares upon
                  exercise of the Warrant, will violate the terms of the
                  certificate of incorporation or by-laws of the Company or, to
                  the best of the Company's knowledge, any agreement (including
                  any agreement with stockholders), instrument, judgment, decree
                  or statute to which the Company is subject.

                           (b)      As of December 31, 2002, the authorized
                  capital stock of the Company consisted of (i) 99,300,000
                  shares of Common Stock, $0.001 par value per share, 95,000,000
                  shares of which are designated as Class A Common Stock, of
                  which 31,885,896 shares are issued and outstanding, and
                  4,300,000 shares of which are designated as Class B Common
                  Stock, of which 3,869,570 shares are issued and outstanding,
                  and (ii) 10,000,000 shares of Preferred Stock, $0.001 par
                  value per share


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<PAGE>
                  600,000 shares of which are designated as Series A Cumulative
                  Convertible Preferred Stock, of which 39,544 shares are issued
                  and outstanding.

                           (c)      Except as set forth in subparagraph (b)
                  above, and in registration statements filed by the Company
                  under the Act or in any report filed by the Company under the
                  Securities Exchange Act of 1934, as amended, the Company has
                  not authorized any rights (either preemptive or other) or
                  options to subscribe for or purchase from the Company, or any
                  warrants or other agreements providing for or requiring the
                  issuance by the Company of, any capital stock or any
                  securities convertible into or exchangeable for its capital
                  stock.

                           (d)      Sufficient shares of authorized but unissued
                  shares of Common Stock of the Company have been reserved by
                  appropriate corporate action with the prospective exercise of
                  the Warrant, and, the issuance of either the Warrant or the
                  shares of Common Stock upon exercise of the Warrant will not
                  require any further corporate action by the stockholders or
                  directors of the Company, will not be subject to preemptive
                  rights (unless the exercise of the same has been irrevocably
                  waived) in any present stockholders of the Company and will
                  not conflict with any provision of any agreement to which the
                  Company is a party or by which it is bound, and such Common
                  Stock, when issued upon exercise of the Warrant in accordance
                  with its terms, will be duly authorized, fully paid and
                  non-assessable.

         17.      Registration Rights.

                  (a)      Piggy Back Registration Rights. If (but without any
         obligation to do so) the Company shall determine to register (a
         "Company Registration") any of its securities for its own account or
         for any other person (other than a registration under the Act of shares
         issued in connection with any acquisition of any entity or business,
         shares issuable solely upon the exercise of stock options, or shares
         issuable solely pursuant to employee benefit plans or arrangements,
         including registration statements on Form S-4, S-8 or any successor
         form), the Company shall do the following:

                           (i)      promptly give the Holder written notice
                  thereof (which shall include a list of the jurisdictions in
                  which the Company intends to attempt to register or qualify
                  such securities under the applicable blue sky or other state
                  securities laws); and

                           (ii)     include among the securities which it then
                  registers or qualifies all Registrable Securities (as defined
                  below) specified in a written request or requests, made within
                  fifteen (15) days after receipt of the written notice from the
                  Company, by the Holder. The Holder shall have the right to
                  withdraw its request for inclusion of its Registrable
                  Securities in any registration statement by giving written
                  notice to the Company of its request to withdraw. The Company
                  may withdraw a Company Registration at any time prior to the
                  time it becomes effective whether or not the Holder has
                  elected to include Registrable Securities (as defined below)
                  in such registration. For purposes of this Warrant, the term
                  "Registrable Securities" shall mean all shares of Common Stock
                  issued and issuable upon exercise of the Warrant; provided
                  however, that shares of Common Stock which are "Registrable
                  Securities" shall cease to be Registrable Securities (a) upon
                  any sale pursuant to a registration statement under the Act,
                  Section 4(1) of the Act or Rule 144 promulgated under the Act
                  or (b) at such time as such shares of Common Stock are freely
                  saleable under Rule 144(k) promulgated under the Act (or a
                  successor provision).


                                       10
<PAGE>
                  (b)      Limitations of Registration. If and to the extent
         that the Holder shall have, at the time of the delivery of the written
         request referred to in subparagraph (a) above, no present intention of
         selling or distribution, the Company shall be obligated to effect such
         registration, qualification or compliance with respect to the Holder's
         Registrable Securities only if and to the extent, in each case, that
         such registration, qualification and compliance are at the time
         permitted by the applicable statutes or rules and regulations
         thereunder or the practices of the governmental authority concerned.

                  (c)      Registration Procedures. In the case of each
         registration, qualification or compliance pursuant to this Section 17,
         the Company will keep the Holder advised in writing as to the
         initiation of proceedings for such registration, qualification and
         compliance and as to the completion thereof, and will advise the
         Holder, upon written request, of the progress of such proceedings. At
         the expense of the Company, the Company will (i) keep such
         registration, qualification and compliance current and effective for a
         period of the earlier of (A) 120 days, or (B) until the Holder has
         completed the distributions relating thereto, including, without
         limitation, the filing of post-effective amendments and supplements to
         any registration statement or prospectus, as necessary to permit the
         sale or distribution of Registrable Securities not theretofore sold or
         distributed, and (ii) take all necessary action under any applicable
         blue sky or other state securities laws to permit such exercise, sale
         or distribution, all as reasonably requested by such Holder; provided,
         however, that the Company shall not be required in connection therewith
         to qualify as a foreign corporation in any jurisdiction in which it is
         not now so qualified or to take any action that would subject it to
         general consent to service of process or taxation. The Company shall
         not be required to file, cause to become effective or maintain the
         effectiveness of any registration statement that contemplates a
         distribution of securities on a delayed or continuous basis pursuant to
         Rule 415 under the Act.

                  (d)      Registration Rights. Anything to the contrary in
         Section 17 notwithstanding, in connection with any Company
         Registration, the Company shall not be required to include any of the
         Holder's Registrable Securities in such Company Registration unless the
         Holder accepts the terms of the underwriting as agreed upon between the
         Company and the underwriters selected by it (or by other persons
         entitled to select the underwriters), and then only in such quantity as
         the underwriters determine in their sole discretion will not jeopardize
         the success of the offering by the Company or will not adversely affect
         the aggregate proceeds to the Company from the offering. If the total
         amount of securities, including Registrable Securities and all other
         securities requested to be included in such offering by any stockholder
         of the Company, exceeds the amount of securities that the underwriters
         determine in their sole discretion is compatible with the success of
         the offering or the aggregate proceeds to the Company from the
         offering, then the number of Shares to be offered for the account of
         the Holder and all such other persons participating in such
         registration shall be reduced (to zero if necessary) or limited pro
         rata in proportion to the respective number of Shares requested to be
         registered by the Holder and each other person to reduce the total
         number of Shares requested to be included in such offering to the
         number of Shares, if any, recommended by such underwriters.

                  (e)      Indemnification. The Company will indemnify, defend
         and hold harmless the Holder to the fullest extent that such agreement
         is enforceable under applicable law against all claims, losses, damages
         and liabilities (or actions in respect thereof) arising out of or based
         on any untrue statement (or alleged untrue statement) of material fact
         contained therein (or in any related registration statement,
         notification or the like) or any omission (or alleged omission) to
         state therein a material fact required to be stated therein or
         necessary to make the statements therein not misleading, or any
         violation by the Company of any rule or regulation promulgated under
         the Act applicable to the


                                       11
<PAGE>
         Company and relating to action or inaction required of the Company in
         connection with any such registration, qualification or compliance, and
         will reimburse the Holder for any legal or any other expenses
         reasonably incurred in connection with investigating or defending any
         such claim, loss, damage, liability or action provided, however, that
         the Company will not be liable in any such case to the extent that any
         such claim, loss, damage or liability arises out of or is based on any
         untrue statement or omission based upon written information furnished
         to the Company by an instrument duly executed by the Holder and stated
         to be specifically for use therein.

                  (f)      The Holder will indemnify, defend and hold harmless
         the Company to the fullest extent that such agreement is enforceable
         under applicable law against all claims, losses, damages and
         liabilities (or actions in respect thereof) arising out of or based on
         any untrue statement (or alleged untrue statement) of material fact
         contained therein (or in any related registration statement,
         notification or the like) or any omission (or alleged omission) to
         state therein a material fact required to be stated therein or
         necessary to make the statements therein not misleading, or any
         violation by the Holder of any rule or regulation promulgated under the
         Act applicable to the Holder and relating to action or inaction
         required of the Holder in connection with any such registration,
         qualification or compliance, and will reimburse the Company for any
         legal or any other expenses reasonably incurred in connection with
         investigating or defending any such claim, loss, damage, liability or
         action, in each case to the extent (and only to the extent) that such
         claims, losses, damages, liabilities and actions relate to reliance on
         any untrue statement or omission based upon written information
         furnished to the Company by an instrument duly executed by the Holder
         and stated to be specifically for use in the registration statement,
         provided, however, that such Holder's obligations hereunder shall be
         limited to an amount equal to the proceeds received by such Holder of
         the Registrable Securities sold in such registration.

                  (g)      Notwithstanding the foregoing, to the extent that the
         provisions on indemnification contained in the underwriting agreement
         entered into in connection with a Company Registration are in conflict
         with the provisions of this Section 17, the provisions in the
         underwriting agreement shall control.

         18.      Binding Effect on Successors. This Warrant shall be binding
upon any corporation succeeding the Company by merger, consolidation or
acquisition of all or substantially all of the Company's assets, and all of the
obligations of the Company relating to the Shares issuable upon exercise of this
Warrant shall survive the exercise and termination of this Warrant and all of
the covenants and agreements of the Company shall inure to the benefit of the
successors and assigns of the Holder.

         19.      Amendments. No approval, consent, amendment or waiver of this
Agreement shall be effective unless in writing and signed by the Company and
Holder.

         20.      Counterparts. This Agreement may be executed in any number of
counterparts and each such counterpart shall for all purposes be deemed to be an
original, and all such counterparts shall together constitute but one and the
same instrument.

         21.      Governing Law. This Warrant shall be construed and enforced in
accordance with, and the rights of the parties shall be governed by, the laws of
the Commonwealth of Massachusetts.

         22.      Entire Agreement. This Warrant constitutes the entire
agreement among the parties hereto pertaining to the subject matter hereof, and
any and all other written or oral agreements relating to the subject matter
hereof existing among any of the parties hereto are expressly cancelled,
including, but not limited to, the Prior Warrant.


                                       12
<PAGE>
         IN WITNESS WHEREOF, the parties have caused this Warrant to be executed
by their duly authorized representatives as of the date first above written.

                                    NEXTERA ENTERPRISES, INC.,
                                    as Company

                                    By: /s/ Michael P. Muldowney
                                       -----------------------------------------
                                        Michael P. Muldowney
                                        Chief Financial Officer


                                    BANK OF AMERICA, N.A.,
                                    as Lender and Holder

                                    By: /s/ Michael R. Heredia
                                       -----------------------------------------
                                        Michael R. Heredia
                                        Managing Director

                                       13