<PAGE>

                                                                     EXHIBIT 4.2

               AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT
               --------------------------------------------------


                                             November 18, 1999


To each of the several Purchasers named in
Exhibit 1.01 to the Series B Convertible Preferred
------------
Stock Purchase Agreement (the "Purchase Agreement")
                               ------------------
of even date herewith, each holder of the
Series A Preferred Stock (as defined below)
as set forth in Exhibit 1 to this Agreement
(referred to collectively as the "Purchasers")
                                  ----------
and each of Jonathan Burgstone and Asif Satchu
(together, the "Founders")
                --------

Dear Sirs:

     The holders of our Series A Convertible Preferred Stock, par value $.001
per share (the "Series A Preferred Stock") originally entered into this
Agreement on June 28, 1999 in connection with their investment in
Suppliermarket.com, Inc., a Delaware corporation (the "Company" ) with the
                                                       -------
Company and the Founders.  In connection with the purchase on the date hereof of
up to an aggregate of 16,040,040 shares (the "Preferred Shares", which term
                                              ----------------
shall include shares of Series A Preferred Stock) of Series B Convertible
Preferred Stock, par value $.001 per share ("Preferred Stock", which term shall
include the Series A Preferred Stock), of the Company, the parties wish to amend
and restate this Agreement and the Company covenants and agrees with each of you
as follows:

     1.   Certain Definitions.  As used in this Agreement, the following terms
          -------------------
shall have the following respective meanings:

     "Blue Sky Application" has the meaning set forth in Section 9.
      --------------------

     "Commission" shall mean the Securities and Exchange Commission, or any
      ----------
other federal agency at the time administering the Securities Act.

     "Common Stock" shall mean the Common Stock, par value $.001 per share, of
      ------------
the Company, as constituted as of the date of this Agreement.

     "Company" has the meaning set forth in the preamble to this Agreement.
      -------

     "Conversion Shares" shall mean shares of Common Stock issued or issuable
      -----------------
upon conversion of the Preferred Shares, and any shares of capital stock
received in respect thereof.


<PAGE>

     "Exchange Act" shall mean the Securities Exchange Act of 1934 or any
      ------------
similar federal statute, and the rules and regulations of the Commission
thereunder, all as the same shall be in effect at the time.

     "Founders" has the meaning set forth in the preamble to this Agreement.
      --------

     "Preferred Shares" shall have the meaning set forth in the preamble to this
      ----------------
Agreement and shall include any additional shares of Preferred Stock issued by
the Company.

     "Preferred Stock" has the meaning set forth in the preamble to this
      ---------------
Agreement.

     "Purchasers" has the meaning set forth in the preamble to this Agreement.
      ----------

     "Registrable Common Shares" shall mean the shares of Common Stock now owned
      -------------------------
or hereafter acquired by the Founders.

     "Registration Expenses" shall have the meaning set forth in Section 8.
      ---------------------

     "Registration Statements" has the meaning set forth in Section 6.
      -----------------------

     "Restricted Stock" shall mean the Conversion Shares and the Registrable
      ----------------
Common Shares, excluding Conversion Shares and Registrable Common Shares which
have been (a) registered under the Securities Act pursuant to an effective
registration statement filed thereunder and disposed of in accordance with the
registration statement covering them or (b) publicly sold pursuant to Rule 144
under the Securities Act; provided, however, that the term "Restricted Stock"
                          --------  -------
shall exclude the Registrable Common Shares for purposes of Sections 4, 6, 13(d)
and 13(h), and, the holders of Registrable Common Shares shall not have any
rights under said Sections 4(a), 4(b) and 6(a).

     "Securities Act" shall mean the Securities Act of 1933 or any similar
      --------------
federal statute, and the rules and regulations of the Commission thereunder, all
as the same shall be in effect at the time.

     "Selling Expenses" shall have the meaning set forth in Section 8.
      ----------------

     "Series A Preferred Stock" has the meaning set forth in the preamble to
      ------------------------
this Agreement.

     "Suspension" has the meaning set forth in Section 6.
      ----------

     2.   Restrictive Legend.  Each certificate representing Preferred Shares,
          ------------------
Conversion Shares or Restricted Stock shall, except as otherwise provided in
this Section 2 or in Section 3, be stamped or otherwise imprinted with a legend
substantially in the following form:

          The securities represented by this certificate have not been
registered under the Securities Act of 1933 or applicable state securities laws.
These securities have been acquired

                                       2
<PAGE>

for investment and not with a view to distribution or resale, and may not be
sold, mortgaged, pledged, hypothecated or otherwise transferred without an
effective registration statement for such securities under the Securities Act of
1933 and applicable state securities laws, or the availability of an exemption
from the registration provisions of the Securities Act of 1933 and applicable
state securities laws.

A certificate shall not bear such legend if in the opinion of counsel reasonably
satisfactory to the Company (it being agreed that Testa, Hurwitz & Thibeault,
LLP and Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP shall be
satisfactory) the securities being sold thereby may be publicly sold without
registration under the Securities Act.

     3.   Notice of Proposed Transfer.  Prior to any proposed transfer of any
          ---------------------------
Preferred Shares, Conversion Shares or Restricted Stock (other than under the
circumstances described in Sections 4, 5 or 6), the holder thereof shall give
written notice to the Company of its intention to effect such transfer.  Each
such notice shall describe the manner of the proposed transfer and, if requested
by the Company, shall be accompanied by an opinion of counsel reasonably
satisfactory to the Company (it being agreed that Testa, Hurwitz & Thibeault,
LLP and Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP shall be
satisfactory) to the effect that the proposed transfer may be effected without
registration under the Securities Act, whereupon the holder of such stock shall
be entitled to transfer such stock in accordance with the terms of its notice;
provided, however, that no such opinion of counsel shall be required for a
--------  -------
transfer to one or more partners of the transferor (in the case of a transferor
that is a partnership), to one or more members of the transferor (in the case of
a transferor that is a limited liability company) or to an affiliated
corporation (in the case of a transferor that is a corporation); provided,
                                                                 --------
further, however, that any transferee other than a partner or affiliate of the
-------  -------
transferor shall execute and deliver to the Company a representation letter in
form reasonably satisfactory to the Company's counsel to the effect that the
transferee is acquiring Restricted Stock for its own account, for investment
purposes and without any view to distribution thereof, and further agreeing to
become bound to this Agreement as a holder of Restricted Stock .  Each
certificate for Preferred Shares or Conversion Shares or Restricted Stock
transferred as above provided shall bear the legend set forth in Section 2,
except that such certificate shall not bear such legend if (i) such transfer is
in accordance with the provisions of Rule 144 (or any other rule permitting
public sale without registration under the Securities Act) or (ii) the opinion
of counsel referred to above is to the further effect that the transferee and
any subsequent transferee (other than an affiliate of the Company) would be
entitled to transfer such securities in a public sale without registration under
the Securities Act.  The restrictions provided for in this Section 3 shall not
apply to securities which are not required to bear the legend prescribed by
Section 2 in accordance with the provisions of that Section.  If the Company
does not accept an opinion of counsel required hereby signed by Testa, Hurwitz &
Thibeault, LLP or Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP,
the Company will pay the reasonable fees and disbursements of other counsel in
connection with all opinions rendered by them pursuant to this Section 3.

                                       3
<PAGE>

     4.   Required Registration.
          ---------------------

          (a)  At any time after the earlier of (i) the third anniversary of
this Agreement, and (ii) 90 days after the Company's initial public offering of
its securities under the Securities Act, the holders of Restricted Stock
constituting at least 35% of the voting power of the total shares of Restricted
Stock then outstanding may request the Company to register under the Securities
Act all or any portion of the shares of Restricted Stock held by such requesting
holder or holders for sale in the manner specified in such notice; provided,
                                                                   --------
however, that the only securities which the Company shall be required to
-------
register pursuant hereto shall be shares of Common Stock; provided, further,
                                                          --------  -------
however, that, in any underwritten public offering contemplated by this Section
-------
4 or Sections 5 and 6, the holders of Preferred Shares shall be entitled to sell
such Preferred Shares to the underwriters for conversion and sale of the shares
of Common Stock issued upon conversion thereof. Notwithstanding anything to the
contrary contained herein, no request may be made under this Section 4 within
180 days after the effective date of a registration statement filed by the
Company covering a firm commitment underwritten public offering in which the
holders of Restricted Stock shall have been entitled to join pursuant to
Sections 5 or 6.

          (b)  Following receipt of any notice under this Section 4, the Company
shall immediately notify all holders of Restricted Stock from whom notice has
not been received and such holders shall then be entitled within 30 days
thereafter to request the Company to include in the requested registration all
or any portion of their shares of Restricted Stock.  The Company shall use its
best efforts to register under the Securities Act, for public sale in accordance
with the method of disposition described in paragraph (a) above, the number of
shares of Restricted Stock specified in such notice (and in all notices received
by the Company from other holders within 30 days after the giving of such notice
by the Company).  The Company shall be obligated to register Restricted Stock
pursuant to this Section 4 on three occasions only; provided, however, that such
                                                    --------  -------
obligation shall be deemed satisfied only when a registration statement covering
all shares of Restricted Stock specified in notices received as aforesaid for
sale in accordance with the method of disposition specified by the requesting
holders shall have become effective or if such registration statement has been
withdrawn prior to the consummation of the offering at the request of the
holders of a majority of the voting power of the Restricted Stock to be
registered (other than as a result of a material adverse change in the business
or condition, financial or otherwise, of the Company) and, if such method of
disposition is a firm commitment underwritten public offering, all such shares
shall have been sold pursuant thereto.

          (c)  The Company and the Founders (or at the option of the Company,
any other holders of Common Stock) shall be entitled to include in any
registration statement referred to in this Section 4 or any registration
statement filed at the request of the holders of Restricted Stock pursuant to
Section 6, for sale in accordance with the method of disposition specified by
the requesting holders of Restricted Stock, shares of Common Stock to be sold by
the Company or such other holders of Common Stock for its own account, except as
and to the extent that, in the opinion of the managing underwriter (if such
method of disposition shall be an underwritten public offering), such inclusion
would adversely affect the marketing of the Restricted Stock to

                                       4
<PAGE>

be sold. Except for registration statements on Form S-4, S-8 or any successor
thereto, the Company will not file with the Commission any other registration
statement with respect to its Common Stock, whether for its own account or that
of other stockholders, from the date of receipt of a notice from requesting
holders pursuant to this Section 4 until the completion of the period of
distribution of the registration contemplated thereby.

          (d)  If in the opinion of the managing underwriter the inclusion of
all of the Restricted Stock requested to be registered under this Section would
adversely affect the marketing of such shares, shares to be sold by the holders
of Restricted Stock shall be excluded only after any shares to be sold by the
Company, the Founders and other holders of Common Stock have been excluded, in
such manner that the shares to be sold shall be allocated among the selling
holders pro rata based on their ownership of Restricted Stock.

          (e)  In the event of an underwritten offering of shares of Restricted
Stock, holders of a majority of the voting power of the shares of Restricted
Stock to be registered and sold in such underwritten offering may select the
lead underwriter which shall be reasonably acceptable to the Company.

     5.   Incidental Registration.  If the Company at any time (other than
          -----------------------
pursuant to Section 4 or Section 6) proposes to register any of its securities
under the Securities Act for sale to the public, whether for its own account or
for the account of other security holders or both (except with respect to
registration statements on Forms S-4, S-8 or another form not available for
registering the Restricted Stock for sale to the public), each such time it will
give written notice to all holders of outstanding Restricted Stock of its
intention so to do.  Upon the written request of any such holder, received by
the Company within 30 days after the giving of any such notice by the Company,
to register any of its Restricted Stock, the Company will use its best efforts
to cause the Restricted Stock as to which registration shall have been so
requested to be included in the securities to be covered by the registration
statement proposed to be filed by the Company, all to the extent requisite to
permit the sale or other disposition by the holder (in accordance with its
written request) of such Restricted Stock so registered.  In the event that any
registration pursuant to this Section 5 shall be, in whole or in part, an
underwritten public offering of Common Stock, the number of shares of Restricted
Stock to be included in such an underwriting may be reduced (pro rata among the
requesting holders based upon the number of shares of Restricted Stock held by
such requesting holders) if and to the extent that the managing underwriter
shall be of the opinion that such inclusion would adversely affect the marketing
of the securities to be sold by the Company therein; provided, however, that
                                                     --------  -------
such number of shares of Restricted Stock shall not be reduced if any shares are
to be included in such underwriting for the account of any person other than the
Company or requesting holders of Restricted Stock; provided, further, however,
                                                   --------  -------  -------
that in no event shall the number of shares of Restricted Stock included in the
offering be reduced below 30% of the total number of shares of Common Stock
included in such offering, unless the offering is the Company's initial public
offering of the Company's securities in which case the number of shares of
Restricted Stock to be included by the holders may be reduced or eliminated
entirely as set forth above.  Notwithstanding the

                                       5
<PAGE>

foregoing provisions, the Company may withdraw any registration statement
referred to in this Section 5 without thereby incurring any liability to the
holders of Restricted Stock.

     6.   Registration on Form S-3.  (a)  If at any time (i) a holder or holders
          ------------------------
of Restricted Stock then outstanding request that the Company file a
registration statement on Form S-3 or any successor thereto for a public
offering of all or any portion of the shares of Restricted Stock held by such
requesting holder or holders, and (ii) the Company is a registrant entitled to
use Form S-3 or any successor thereto to register such shares, then the Company
shall use its best efforts to register under the Securities Act on Form S-3 or
any successor thereto, for public sale in accordance with the method of
disposition specified in such notice, the number of shares of Restricted Stock
specified in such notice.  Whenever the Company is required by this Section 6 to
use its best efforts to effect the registration of Restricted Stock, each of the
procedures and requirements of Section 4 (including but not limited to the
requirement that the Company notify all holders of Restricted Stock from whom
notice has not been received and provide them with the opportunity to
participate in the offering) shall apply to such registration; provided,
                                                               --------
however, that there shall be no limitation on the number of registrations on
-------
Form S-3 which may be requested and obtained under this Section 6.

          (b)  Notwithstanding anything to the contrary set forth in this
Agreement, the Company's obligation under this Agreement to register Restricted
Stock under the Securities Act on registration statements ("Registration
Statements") may, upon the reasonable determination of the Board of Directors
made only once during any 12-month period, be suspended in the event and during
such period as unforeseen circumstances (including without limitation (i) an
underwritten primary offering by the Company (which includes no secondary
offering) if the Company is advised in writing by its underwriters that the
registration of the Restricted Stock would have a material adverse effect on the
Company's offering, or (ii) pending negotiations relating to, or consummation
of, a transaction or the occurrence of an event which would require additional
disclosure of material information by the Company in Registration Statements or
such other filings, as to which the Company has a bona fide business purpose for
preserving confidentiality or which renders the Company unable to comply with
Securities and Exchange Commission (the "SEC") requirements) exist (such
unforeseen circumstances being hereinafter referred to as a "Suspension Event")
which would make it impractical or unadvisable for the Company to file the
Registration Statements or such other filings or to cause such to become
effective.  Such suspension shall continue only for so long as such event is
continuing but in no event for a period longer than 90 days.  The Company shall
notify the Purchasers of the existence and nature of any Suspension Event.

     7.   Registration Procedures.  If and whenever the Company is required by
          -----------------------
the provisions of Sections 4, 5 or 6 to use its best efforts to effect the
registration of any shares of Restricted Stock under the Securities Act, the
Company will, as expeditiously as possible:

          (a)  prepare and file with the Commission a registration statement
(which, in the case of an underwritten public offering pursuant to Section 4,
shall be on Form S-1 or other form of general applicability satisfactory to the
managing underwriter selected as therein

                                       6
<PAGE>

provided) with respect to such securities and use its best efforts to cause such
registration statement to become and remain effective for the period of the
distribution contemplated thereby;

          (b)  prepare and file with the Commission such amendments and
supplements to such registration statement and the prospectus used in connection
therewith as may be necessary to keep such registration statement effective for
the period specified in paragraph (a) above and comply with the provisions of
the Securities Act with respect to the disposition of all Restricted Stock
covered by such registration statement in accordance with the sellers' intended
method of disposition set forth in such registration statement for such period;

          (c)  furnish to each seller of Restricted Stock and to each
underwriter such number of copies of the registration statement and each such
amendment and supplement thereto (in each case including all exhibits) and the
prospectus included therein (including each preliminary prospectus) as such
persons reasonably may request in order to facilitate the public sale or other
disposition of the Restricted Stock covered by such registration statement;

          (d)  use its best efforts to register or qualify the Restricted Stock
covered by such registration statement under the securities or "blue sky" laws
of such jurisdictions as the sellers of Restricted Stock or, in the case of an
underwritten public offering, the managing underwriter reasonably shall request;
provided, however, that the Company shall not for any such purpose be required
--------  -------
to qualify generally to transact business as a foreign corporation in any
jurisdiction where it is not so qualified or to consent to general service of
process in any such jurisdiction;

          (e)  use its best efforts to list the Restricted Stock covered by such
registration statement with any securities exchange on which the Common Stock of
the Company is then listed;

          (f)  immediately notify each seller of Restricted Stock and each
underwriter under such registration statement, at any time when a prospectus
relating thereto is required to be delivered under the Securities Act, of the
happening of any event of which the Company has knowledge as a result of which
the prospectus contained in such registration statement, as then in effect,
includes an untrue statement of a material fact or omits to state a material
fact required to be stated therein or necessary to make the statements therein
not misleading in light of the circumstances then existing, and promptly prepare
and furnish to such seller a reasonable number of copies of a prospectus
supplemented or amended so that, as thereafter delivered to the purchasers of
such Restricted Stock, such prospectus shall not include an untrue statement of
a material fact or omit to state a material fact required to be stated therein
or necessary to make the statements therein not misleading in light of the
circumstances then existing;

          (g)  if the offering is underwritten and at the request of any seller
of Restricted Stock, use its best efforts to furnish on the date that Restricted
Stock is delivered to the underwriters for sale pursuant to such registration:
(i) an opinion dated such date of counsel

                                       7
<PAGE>

representing the Company for the purposes of such registration, addressed to the
underwriters and to such seller, to such effect as reasonably may be requested
by counsel for the underwriters, and (ii) a letter dated such date from the
independent public accountants retained by the Company, addressed to the
underwriters and to such seller, stating that they are independent public
accountants within the meaning of the Securities Act and that, in the opinion of
such accountants, the financial statements of the Company included in the
registration statement or the prospectus, or any amendment or supplement
thereof, comply as to form in all material respects with the applicable
accounting requirements of the Securities Act, and such letter shall
additionally cover such other financial matters (including information as to the
period ending no more than five business days prior to the date of such letter)
with respect to such registration as such underwriters reasonably may request;

          (h)  provide each seller of Restricted Stock, any underwriter
participating in any distribution pursuant to such registration statement, and
any attorney, accountant or other agent retained by such seller or underwriter,
reasonable access to all financial and other records, pertinent corporate
documents and properties of the Company, as such parties may reasonably request,
and cause the Company's officers, directors and employees to supply all
information reasonably requested by any such seller, underwriter, attorney,
accountant or agent in connection with such registration statement;

          (i)  cooperate with the selling holders of Restricted Stock and the
managing underwriters, if any, to facilitate the timely preparation and delivery
of certificates representing Restricted Stock to be sold, such certificates to
be in such denominations and registered in such names as such holders or the
managing underwriters may request at least two business days prior to any sale
of Restricted Stock;

          (j)  permit any holder of Restricted Stock which holder, in the sole
and exclusive judgment, exercised in good faith, of such holder, might be deemed
to be a controlling person of the Company, to participate in good faith in the
preparation of such registration or comparable statement and to require the
insertion therein of material, furnished to the Company in writing, which in the
reasonable judgment of such holder and its counsel should be included; and

          (k)  provide a transfer agent and registrar for all Restricted Stock
to be registered not later than the effective date of such registration
statement and obtain a CUSIP number as needed.

          For purposes of Section 7(a) and 7(b) and of Section 4(c), the period
of distribution of Restricted Stock in a firm commitment underwritten public
offering shall be deemed to extend until each underwriter has completed the
distribution of all securities purchased by it, and the period of distribution
of Restricted Stock in any other registration shall be deemed to extend until
the earlier of the sale of all Restricted Stock covered thereby and 180 days
after the effective date thereof.

                                       8
<PAGE>

          In connection with each registration hereunder, the sellers of
Restricted Stock will furnish to the Company in writing such information
requested by the Company with respect to themselves and the proposed
distribution by them as reasonably shall be necessary in order to assure
compliance with federal and applicable state securities laws.

          In connection with each registration pursuant to Sections 4, 5 or 6
covering an underwritten public offering, the Company and each seller agree to
enter into a written agreement with the managing underwriter selected in the
manner herein provided in such form and containing such provisions as are
customary in the securities business for such an arrangement between such
underwriter and companies of the Company's size and investment stature.

     8.   Expenses.  All expenses incurred by the Company in complying with
          --------
Sections 4, 5 and 6, including, without limitation, all registration and filing
fees, printing expenses, fees and disbursements of counsel and independent
public accountants for the Company, fees and expenses (including counsel fees)
incurred in connection with complying with state securities or "blue sky" laws,
fees and expenses of one counsel for the selling holders of Restricted Stock in
connection with the registration of Restricted Stock, fees of the National
Association of Securities Dealers, Inc., transfer taxes, fees of transfer agents
and registrars, costs of any insurance which might be obtained, but excluding
any Selling Expenses, are called "Registration Expenses."  All underwriting
discounts and selling commissions applicable to the sale of Restricted Stock and
the fees and expenses of more than one counsel for the selling holders of
Restricted Stock in connection with the registration of Restricted Stock are
called "Selling Expenses."

          The Company will pay all Registration Expenses in connection with each
registration statement under Sections 4, 5 or 6.  All Selling Expenses in
connection with each registration statement under Sections 4, 5 or 6 shall be
borne by the participating sellers in proportion to the number of shares sold by
each, or by such participating sellers other than the Company (except to the
extent the Company shall be a seller) as they may agree.

     9.   Indemnification.
          ---------------

          (a)  In the event of a registration of any of the Restricted Stock
under the Securities Act pursuant to Sections 4, 5 or 6, the Company will
indemnify and hold harmless each holder of Restricted Stock, its partners,
officers and directors, each underwriter of such Restricted Stock thereunder and
each other person, if any, who controls such holder or underwriter within the
meaning of the Securities Act, against any losses, claims, damages or
liabilities, joint or several, to which such holder, partner, officer, director,
underwriter or controlling person may become subject under the Securities Act or
otherwise, insofar as such losses, claims, damages or liabilities (or actions in
respect thereof) arise out of or are based upon (i) any untrue statement or
alleged untrue statement of any material fact contained in any registration
statement under which such Restricted Stock was registered under the Securities
Act pursuant to Sections 4, 5 or 6, any preliminary prospectus or final
prospectus contained therein, or any amendment or supplement thereof, (ii) any
blue sky application or other document

                                       9
<PAGE>

executed by the Company specifically for that purpose or based upon written
information furnished by the Company filed in any state or other jurisdiction in
order to qualify any or all of the Restricted Stock under the securities laws
thereof (any such application, document or information herein called a "Blue Sky
Application"), (iii) the omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, (iv) any violation by the Company or its agents of any
rule or regulation promulgated under the Securities Act applicable to the
Company or its agents and relating to action or inaction required of the Company
in connection with such registration, or (v) any failure to register or qualify
the Restricted Stock in any state where the Company or its agents has
affirmatively undertaken or agreed in writing that the Company (the undertaking
of any underwriter chosen by the Company being attributed to the Company) will
undertake such registration or qualification on the seller's behalf (provided
that in such instance the Company shall not be so liable if it has undertaken
its best efforts to so register or qualify the Restricted Stock) and will
reimburse each such holder, and such partner, officer and director, each such
underwriter and each such controlling person for any legal or other expenses
reasonably incurred by them in connection with investigating or defending any
such loss, claim, damage, liability or action; provided, however, that the
                                               --------  -------
Company will not be liable in any such case if and to the extent that any such
loss, claim, damage or liability arises out of or is based upon an untrue
statement or alleged untrue statement or omission or alleged omission so made in
conformity with information furnished by any such holder, any such underwriter
or any such controlling person in writing specifically for use in such
registration statement or prospectus.

          (b)  In the event of a registration of any of the Restricted Stock
under the Securities Act pursuant to Sections 4, 5 or 6, each seller of such
Restricted Stock thereunder, severally and not jointly, will indemnify and hold
harmless the Company, each person, if any, who controls the Company within the
meaning of the Securities Act, each officer of the Company who signs the
registration statement, each director of the Company, each other seller of
Restricted Stock, each underwriter and each person who controls any seller or
underwriter within the meaning of the Securities Act, against all losses,
claims, damages or liabilities, joint or several, to which the Company or such
officer, director, other seller, underwriter or controlling person may become
subject under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon any untrue statement or alleged untrue statement of any material fact
contained in the registration statement under which such Restricted Stock was
registered under the Securities Act pursuant to Sections 4, 5 or 6, any
preliminary prospectus or final prospectus contained therein, or any amendment
or supplement thereof, or any Blue Sky Application or arise out of or are based
upon the omission or alleged omission to state therein a material fact required
to be stated therein or necessary to make the statements therein not misleading,
and will reimburse the Company and each such officer, director, other seller,
underwriter and controlling person for any legal or other expenses reasonably
incurred by them in connection with investigating or defending any such loss,
claim, damage, liability or action; provided, however, that such seller will be
                                    --------  -------
liable hereunder in any such case if and only to the extent that any such loss,
claim, damage or liability arises out of or is based upon an untrue statement or
alleged untrue statement or omission or alleged omission made in reliance upon
and in conformity with information pertaining to such

                                       10
<PAGE>

seller, as such, furnished in writing to the Company by such seller specifically
for use in such registration statement or prospectus; and provided, further,
                                                          --------  -------
however, that the liability of each seller hereunder shall not exceed the
-------
proceeds received by such seller from the sale of Restricted Stock covered by
such registration statement.

          (c)  Promptly after receipt by an indemnified party hereunder of
notice of the commencement of any action, such indemnified party shall, if a
claim in respect thereof is to be made against the indemnifying party hereunder,
notify the indemnifying party in writing thereof, but the omission so to notify
the indemnifying party shall not relieve it from any liability which it may have
to such indemnified party other than under this Section 9 and shall only relieve
it from any liability which it may have to such indemnified party under this
Section 9 if and to the extent the indemnifying party is prejudiced by such
omission. In case any such action shall be brought against any indemnified party
and it shall notify the indemnifying party of the commencement thereof, the
indemnifying party shall be entitled to participate in and, to the extent it
shall wish, to assume and undertake the defense thereof with counsel
satisfactory to such indemnified party, and, after notice from the indemnifying
party to such indemnified party of its election so to assume and undertake the
defense thereof, the indemnifying party shall not be liable to such indemnified
party under this Section 9 for any legal expenses subsequently incurred by such
indemnified party in connection with the defense thereof other than reasonable
costs of investigation and of liaison with counsel so selected; provided,
                                                                --------
however, that, if the defendants in any such action include both the indemnified
-------
party and the indemnifying party and the indemnified party shall have reasonably
concluded that the interests of the indemnified party reasonably may be deemed
to conflict with the interests of the indemnifying party, the indemnified party
shall have the right to select a separate counsel and to assume such legal
defenses and otherwise to participate in the defense of such action, with the
expenses and fees of such separate counsel and other expenses related to such
participation to be reimbursed by the indemnifying party as incurred. If the
indemnification provided for in this Section 9 is held by a court of competent
jurisdiction to be unavailable by reason of unenforceability to an indemnified
party with respect to any loss, liability, claim, damage or expense referred to
herein, then the indemnifying party, in lieu of indemnifying such indemnified
party hereunder, shall contribute to the amount paid or payable by such
indemnified party as a result of such loss, liability, claim, damage or expense
in such proportion as is appropriate to reflect the relative fault of the
indemnifying party on the one hand and of the indemnified party on the other in
connection with the statements or omissions that resulted in such loss,
liability, claim, damage or expense, as well as any other relevant equitable
considerations. The relative fault of the indemnifying party and of the
indemnified party shall be determined primarily by reference to whether the
untrue or alleged untrue statement of a material fact or the omission to state a
material fact relates to information supplied by the indemnifying party or by
the indemnified party and secondarily by reference to, among other things, the
parties' relative intent, knowledge, access to information, and opportunity to
correct or prevent such statement or omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.

                                       11
<PAGE>

          (d)  The indemnities provided in this Section 9 shall survive the
transfer of any Restricted Stock by such holder.

     10.  Changes in Common Stock or Preferred Stock.  If, and as often as,
          ------------------------------------------
there is any change in the Common Stock or the Preferred Stock by way of a stock
split, stock dividend, combination or reclassification, or through a merger,
consolidation, reorganization or recapitalization, or by any other means,
appropriate adjustment shall be made in the provisions hereof so that the rights
and privileges granted hereby shall continue with respect to the Common Stock or
the Preferred Stock as so changed.

     11.  Rule 144 Reporting.  With a view to making available the benefits of
          ------------------
certain rules and regulations of the Commission which may at any time permit the
sale of the Restricted Stock to the public without registration, the Company
agrees to:

          (a)  make and keep public information available, as those terms are
understood and defined in Rule 144 under the Securities Act at all times after
the Company's initial public offering;

          (b)  use its best efforts to file with the Commission in a timely
manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act; and

          (c)  furnish to each holder of Restricted Stock forthwith upon request
a written statement by the Company as to its compliance with the reporting
requirements of such Rule 144 and of the Securities Act and the Exchange Act or
that it qualifies as a registrant whose securities may be resold pursuant to
Form S-3, a copy of the most recent annual or quarterly report of the Company,
and such other reports and documents so filed by the Company as such holder may
reasonably request in availing itself of any rule or regulation of the
Commission allowing such holder to sell any Restricted Stock without
registration.

     12.  Representations and Warranties of the Company.  The Company represents
          ---------------------------------------------
and warrants to you as follows:

          (a)  The execution, delivery and performance of this Agreement by the
Company have been duly authorized by all requisite corporate action and will not
violate any provision of law, any order of any court or other agency of
government, the certificate of incorporation or bylaws of the Company or any
provision of any indenture, agreement or other instrument to which it or any or
its properties or assets is bound, conflict with, result in a breach of or
constitute (with due notice or lapse of time or both) a default under any such
indenture, agreement or other instrument or result in the creation or imposition
of any lien, charge or encumbrance of any nature whatsoever upon any of the
properties or assets of the Company.

          (b)  This Agreement has been duly executed and delivered by the
Company and constitutes the legal, valid and binding obligation of the Company,
enforceable in accordance

                                       12
<PAGE>

with its terms, except to the extent the indemnification provisions herein may
be deemed not enforceable.

     13.  Miscellaneous.
          -------------

          (a)  All covenants and agreements contained in this Agreement by or on
behalf of any of the parties hereto shall bind and inure to the benefit of the
respective successors and assigns of the parties hereto (including without
limitation transferees of any Preferred Shares or Restricted Stock), whether so
expressed or not; provided, however, that registration rights conferred herein
                  --------  -------
on the holders of Preferred Shares or Restricted Stock shall only inure to the
benefit of a transferee of Preferred Shares or Restricted Stock if (a)(i) there
is transferred to such transferee at least 50,000 shares of the Restricted Stock
(appropriately adjusted for any subdivision or combination) originally issued to
the holder or to the direct or indirect transferor of such transferee or (ii)
such transferee is a partner, member, shareholder or affiliate of a party
hereto, and (b) such transferee signs a counterpart signature page agreeing to
become a party to this Agreement.

          (b)  All notices, requests, consents and other communications
hereunder shall be in writing and mailed, faxed or delivered to each applicable
party as follows:

          if to the Company or any other party hereto, at the address of such
party set forth in a certain Amended and Restated Stockholders Agreement by and
among the parties hereto dated as of the date hereof with a copy to the
Company's counsel as indicated therein;

          if to any subsequent holder of Preferred Shares or Restricted Stock,
to it at such address as may have been furnished to the Company in writing by
such holder;

or, in any case, at such other address or addresses as shall have been furnished
in writing to the Company (in the case of a holder of Preferred Shares or
Restricted Stock) or to the holders of Preferred Shares or Restricted Stock (in
the case of the Company) in accordance with the provisions of this paragraph.

     All such notices, requests, demands and other communications shall be
effective, (a) when mailed (which mailing must be accomplished by certified or
registered mail, return receipt requested, postage prepaid), five days after
deposited in the mails, (b) when sent by express overnight courier service one
day after properly deposited with such courier service, or (c) when faxed upon
transmission by facsimile.

          (c)  This Agreement shall be construed and enforced in accordance with
and governed by the General Corporation Law of the State of Delaware as to
matters within the scope thereof and as to all other matters shall be construed
and enforced in accordance with and

                                       13
<PAGE>

governed by the internal laws of the Commonwealth of Massachusetts, without
regard to its principles of conflicts of laws.

          (d)  This Agreement may not be amended or modified, and no provision
hereof may be waived, without the written consent of the Company and the holders
of at least a majority of the voting power of Restricted Stock.  Notwithstanding
the foregoing, no such amendment or modification shall be effective if and to
the extent that such amendment or modification either (a) creates any additional
affirmative obligations to be complied with by any or all of the Purchasers or
(b) grants to any one or more Purchasers any rights more favorable than any
rights granted to all other Purchasers or otherwise treats any one or more
Purchasers differently than all other Purchasers.


          (e)  This Agreement may be executed in two or more counterparts, each
of which shall be deemed an original, but all of which together shall constitute
one and the same instrument.


          (f)  The obligations of the Company to register shares of Restricted
Stock under Sections 4, 5 or 6 shall terminate six years after completion of an
underwritten public offering of shares of Common Stock in which the net proceeds
received by the Company shall be at least $30 million and the per share price
paid by the public for such shares shall be at least three times the original
purchase price per share paid by the Purchasers under the Purchase Agreement for
the Series B Preferred Stock (appropriately adjusted to reflect any subdivision
or combination).


          (g)  If requested in writing by the underwriters for the initial
underwritten public offering of securities of the Company, each holder of
Restricted Stock who is a party to this Agreement shall agree not to sell
publicly any shares of Restricted Stock (other than shares of Restricted Stock
being registered in such offering), without the consent of such underwriters,
for a period of not more than 180 days following the consummation of such
initial public offering; provided, however, that all persons entitled to
                         --------  -------
registration rights with respect to shares of Common Stock who are not parties
to this Agreement and all executive officers and directors of the Company shall
also have agreed not to sell publicly their Common Stock under the circumstances
and pursuant to the terms set forth in this Section 13(g).


          (h)  The Company shall not grant to any third party any registration
rights comparable to or more favorable than any of those contained herein, so
long as any of the registration rights under this Agreement remains in effect,
without prior written consent of holders of a majority of the voting power of
Restricted Stock.


          (i)  If any provision of this Agreement shall be held to be illegal,
invalid or unenforceable, such illegality, invalidity or unenforceability shall
attach only to such provision and shall not in any manner affect or render
illegal, invalid or unenforceable any other provision of this Agreement, and
this Agreement shall be carried out as if any such illegal, invalid or
unenforceable provision were not contained herein.

                                       14
<PAGE>

          (j)  Any purchaser of Series B Preferred Stock who purchases Preferred
Shares following the date of this Agreement may become a party to this Agreement
by executing and delivering to the Company a counterpart to this Agreement.
Upon such execution and delivery, such purchaser shall be a "Purchaser"
hereunder with all of the rights and obligations thereof, and any shares of
Preferred Stock so purchased shall be deemed to be "Preferred Shares" for all
purposes hereunder.

          (k)  This Agreement amends and restates in its entirety the
Registration Rights Agreement dated as of June 28, 1999 and all parties thereto
as well as all signatories hereto shall be bound under this Agreement.

                                       15
<PAGE>

          Please indicate your acceptance of the foregoing by signing and
returning the enclosed counterpart of this letter, whereupon this Amended and
Registration Rights Agreement shall be a binding agreement among the Company,
the Founders and you.


                                   Very truly yours,



                                   SUPPLIERMARKET.COM, INC.



                                   By:  /s/ Asif Satchu
                                       -------------------------
                                        Name: Asif Satchu
                                        Title: President
<PAGE>

          [Signature Page to Amended and Restated Registration Rights Agreement]


AGREED TO AND ACCEPTED as of the date
first above written.


PURCHASERS OF SERIES B PREFERRED STOCK:


BATTERY VENTURES V, L.P.


By:  Battery Partners V, LLC


By:    /s/ Donald D. Stanley
       --------------------------------
       Chief Financial Officer



BATTERY INVESTMENT PARTNERS V, LLC


By:    /s/ Donald D. Stanley
       --------------------------------
       Chief Financial Officer



BATTERY VENTURES CONVERGENCE FUND, L.P.


By:  Battery Convergence Partners, LLC



By:    /s/ Donald D. Stanley
       -----------------------------
       Chief Financial Officer
<PAGE>

          [Signature Page to Amended and Restated Registration Rights Agreement]



SEQUOIA CAPITAL VIII
SEQUOIA INTERNATIONAL TECHNOLOGY PARTNERS VIII
SEQUOIA INTERNATIONAL TECHNOLOGY PARTNERS VIII(Q)


By:  SC VIII Management, LLC
     A California Limited Liability Company
     General Partner to Each



By:  /s/ Barbara Russell
     ----------------------------------
     Director of Partnership Operations


CMS PARTNERS LLC



By:  /s/ Barbara Russell
     ----------------------------------
     Director of Partnership Operations
<PAGE>

          [Signature Page to Amended and Restated Registration Rights Agreement]



AURORA INVESTMENTS LLC



By: /s/ William Janetshek
    -----------------------------------
        Member
<PAGE>

          [Signature Page to Amended and Restated Registration Rights Agreement]



FENWAY PARTNERS CAPITAL FUND II, L.P.


By:  Fenway Partners II, LLC
     Its General Partner



By:  /s/ Peter Lamm
     ----------------------------------
     Managing Member:
<PAGE>

    [Signature Page to Amended and Restated Registration Rights Agreement]


MADISON DEARBORN CAPITAL PARTNERS III, LP

By:  Madison Dearborn Partners III, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner


By:  /s/ Thomas R. Reusche
     ----------------------------
     A Managing Director


MADISON DEARBORN SPECIAL EQUITY III, LP

By:  Madison Dearborn Partners III, L.P.
Its: General Partner

By:  Madison Dearborn Partners, LLC
Its: General Partner


By:  /s/ Thomas R. Reusche
     ----------------------------
     A Managing Director


SPECIAL ADVISORS FUND I, LLC

By:  Madison Dearborn Partners III, L.P.
Its: Manager

By:  Madison Dearborn Partners, LLC
Its: General Partner


By:  /s/ Thomas R. Reusche
     ----------------------------
     A Managing Director
<PAGE>

    [Signature Page to Amended and Restated Registration Rights Agreement]


OMI PARTNERSHIP HOLDINGS LTD.


By:  /s/ John Troiano
     ------------------------
     Name: John Troiano
     Title: Principal
<PAGE>

          [Signature Page to Amended and Restated Registration Rights Agreement]



CHISHOLM PARTNERS IV, L.P.

By: Chisholm Management IV, L.P., its General
    Partner


By:  /s/ Habib Y. Gorgi
     ----------------------------
     Name: Habib Y. Gorgi
     Title: Managing Director


KENNEDY PLAZA PARTNERS II, LLC

By:  Chisholm Management IV, L.P., its Manager


By:  /s/ Habib Y. Gorgi
     ----------------------------
     Name: Habib Y. Gorgi
     Title: Managing Director


FLEET GROWTH RESOURCES, INC.

By:  /s/ Habib Y. Gorgi
     ----------------------------
     Name: Habib Y. Gorgi
     Title: President


FLEET EQUITY PARTNERS VII, L.P.

By: Fleet Growth Resources, Inc., a General
    Partner


By:  /s/ Habib Y. Gorgi
     ----------------------------
     Name: Habib Y. Gorgi
     Title: President
<PAGE>

By: /s/ Marco Iansiti
   ---------------------------------------------



By: /s/ Michael A. Barr
   ----------------------------------------------



By: /s/ Rustom & Zarina Satchu JTWROS
   ----------------------------------------------



By: /s/ Stanley S. Shuman
   ----------------------------------------------



By: /s/ Stacey A. Lawson
   ----------------------------------------------



By: /s/ J. Jason Phillips and Sheila M. Schroeder
   ----------------------------------------------



By: /s/ Jason R. Schomer
   ----------------------------------------------



By: /s/ Alexander C. Sacerdote
   ----------------------------------------------



By: /s/ Marcos A. Rodriguez
   ----------------------------------------------



By: /s/ James T. & Margaret J. McKitrick
   ----------------------------------------------
<PAGE>

By: /s/ William A. Sahlman
   ------------------------------------



By: /s/ Anthony K. Tjan
   ------------------------------------



By: /s/ Michael J. Roberts
   ------------------------------------



By: /s/ Mark N. Diker
   ------------------------------------



By: /s/ Timothy P. Mayhew
   ------------------------------------



By: /s/ Brian Frank
   ------------------------------------



By: /s/ Terrence M. Mullen
   ------------------------------------



By: /s/ Peter S. Cohan
   ------------------------------------



By: /s/ Jerry J. Jasinowski
   ------------------------------------
<PAGE>

TWO CREEKS CAPITAL PARTNERS, LLC,

 As Nominee


By: /s/ Lawrence D. Stuart, Jr.
    ---------------------------------
    Name: Lawrence D. Stuart, Jr.
    Title: Partner


REPVEST, L.L.C.



By: /s/ Kevin J. Connors
    ---------------------------------
    Name: Kevin J. Connors
    Title: Registered Agent



SKYDOME PARTNERS, LLC



By: /s/ Reza Satchu
    ---------------------------------
    Name: Reza Satchu
    Title: Managing Member



RGIP, LLC



By: /s/ R. B. Malt
    ---------------------------------
    Name: R. B. Malt
    Title: Managing Member


REGIS INVESTMENTS LLC



By: /s/ Gabriele J. Troiano
    ----------------------------------
    Name: Gabriele J. Troiano
    Title: Managing Member
<PAGE>

CHRISTAN AND TIMBERS, INC.



By: /s/ David C. Nocifora
    ---------------------------------
    Name: David C. Nocifora
    Title: Vice President and
           Chief Financial Officer



By: /s/ David A. Snavely
    ---------------------------------
    Name:  David A. Snavely
    Title: The Trust Company of Toledo,
           N.A., Trustee of the Robert
           J. Lanigan Revocable Trust


By: /s/ Karen H. Andrews
    ---------------------------------



By: /s/ Samuel Valenti III
    ---------------------------------



By: /s/
    ---------------------------------
<PAGE>

    [Signature Page to Amended and Restated Registration Rights Agreement]



FOUNDERS:
--------


/s/ Jonathan Burgston
------------------------
Jonathan Burgstone



/s/ Asif Satchu
------------------------
Asif Satchu
<PAGE>

                                                                       Exhibit 1
                                                                       ---------



                              Series A Purchasers



Names and Address
-----------------


Battery Ventures V, L.P.
Battery Investment Partners V, LLC
Battery Ventures Convergence Fund, L.P.
20 William Street
Wellesley, MA 02481
Fax:

Sequoia Capital VIII
Sequoia International Technology Partners VIII
Sequoia International Technology Partners VIII (Q)
CMS Partners LLC
Sequoia 1997
3000 Sand Hill Road
Building 4, Suite 280
Menlo Park, CA 94025

Sky Dome Partners, LLC
c/o Fenway Partners
152 West 57/th/ Street, 59/th/ Floor
New York, NY 10019
Attn: Reza Satchu
Fax: (212) 581-1205

Timothy Mayhew
Palladium Equity Partners
Rockefeller Center
1270 Avenue of the Americas
Suite 2200
New York, NY 10020
Fax: (212) 218-5155
<PAGE>

Stacey Lawson
Parametric Corporation
128 Technology Drive
Waltham, MA 02453
Fax: (781) 398-6170

Judy Walsh
The Career Group
One Kendall Square, Building 200
Cambridge, MA 02139
Fax: (617) 494-5210

Jay O. Light
Harvard Business School
Morgan Hall 489
Soldiers Field
Boston, MA 02163
Fax: (617) 496-8443

Marco Iansiti
Harvard Business School
Morgan Hall T69
Soldiers Field
Boston, MA 02163
Fax: (617) 496-4072

William A. Sahlman
Harvard Business School
Baker Library 373
Soldiers Field
Boston, MA 02163
Fax: (617) 495-9319

Michael Roberts
Harvard Business School
Baker Library 287
Soldiers Field
Boston, MA 02163
Fax:
<PAGE>

Mike Diker
GeoCapital Partners
2 Executive Drive, Suite 820
Fort Lee, NJ 07024
Fax: (201) 461-9292

Rustom Satchu
11 Salonica Road
Toronto, Ontario M3C 2L6
Fax: (416) 360-8248

Cynthia Ringo
Coopercom, Inc.
3255-1 Scott Blvd, Ste 103
Santa Clara, CA 95054
Fax: (408) 567-9558

Stanley Shuman
Allen & Company
711 5/th/ Avenue, 9/th/ Floor (@55/th/)
New York, NY 10022
Fax: (212)339-2305

Marcos Rodriquez
Palladium Equity Partners
Rockefeller Center
1270 Avenue of the Americas
Suite 2200
New York, NY 10020
Fax:

Mr. Chris Brody
610 5/th/ Avenue, 7/th/ Floor
New York, NY 10017
Fax:

Peter Cohan
Peter Cohan & Associates
Two Turner Ridge Road
Marlborough, MA 01752
Fax: