VOTING AGREEMENT


     Agreement  (this  "Agreement")  made  as of  March  2,  2000  by and  among
VerticalBuyer,  Inc.,  a  Delaware  corporation  (the  "Company"),  CSP Inc.,  a
Massachusetts  corporation ("CSPI"),  Tim Rosen ("First Stockholder") and Leslie
Kent  ("Second  Stockholder"  and,  collectively  with  First  Stockholder,  the
"Stockholders").  (The parties to this Agreement will hereinafter be referred to
as the "Parties.")

     In  consideration of the mutual  covenants  herein  contained,  the Parties
agree as follows:

     1. Board of Directors;  By-Laws.  The Stockholders  will vote all shares of
common  stock,  preferred  stock  or any  other  class  of  voting  security  of
VerticalBuyer  now or hereafter owned or controlled by them (the "Shares"),  and
otherwise to use their respective best efforts as stockholders of VerticalBuyer,
to elect one person  designated  by CSPI as a director of  VerticalBuyer  in any
subsequent  election of directors of VerticalBuyer.  The initial nominee of CSPI
to be director is Alexander  Lupinetti,  Chairman of the Board of Directors  and
President of CSPI.

     VerticalBuyer  and the Stockholders  agree not to take any action to remove
the person designated or nominated by CSPI as director,  to change the number of
directors constituting the full Board of Directors, or to amend any provision of
the Certificate of  Incorporation  or By-Laws of  VerticalBuyer  relating to the
election and number of  directors,  as  presently  in effect,  without the prior
written consent of CSPI.

     2. Conduct of Business of VerticalBuyer. During the period from the date of
this  Agreement  and  continuing  until  the  effective  date of a  registration
statement  filed with the  Securities  and Exchange  Commission  relating to the
Shares  purchased  by CSPI and the Shares  underlying  the warrant  purchased by
CSPI,  VerticalBuyer  shall  not  do,  cause  or  permit  and  shall  cause  its
subsidiaries  not to do,  cause or permit,  any of the  following,  without  the
affirmative   vote  of  the  person   designated   by  CSPI  as  a  director  of
VerticalBuyer:

     (a)  Material Contracts. Enter into any material contract or commitment, or
          violate, amend or otherwise modify or waive any of the terms of any of
          its material contracts,  other than in the ordinary course of business
          consistent with past practice;

     (b)  Issuance of Securities. Issue, deliver or sell or authorize or propose
          the issuance, delivery or sale of, or purchase or propose the purchase
          of, any shares of its capital stock or securities convertible into, or
          subscriptions,  rights,  warrants  or  options  to  acquire,  or other
          agreements or commitments of any character  obligating it to issue any
          such shares or other convertible securities.

     (c)  Intellectual Property.  Transfer to any person or entity any rights to
          its  intellectual  property  other  than  in the  ordinary  course  of
          business consistent with past practice.

     (d)  Exclusive Rights. Enter into or amend any material agreements pursuant
          to which any  other  party is  granted  exclusive  marketing  or other
          exclusive  rights  of any type or  scope  with  respect  to any of its
          services.


<PAGE>

     (e)  Dispositions. Sell, lease, license or otherwise dispose of or encumber
          any of its properties or assets which are material, individually or in
          subsidiaries'  business,  taken as a  whole,  except  in the  ordinary
          course of business consistent with past practice;

     (f)  Indebtedness.  Incur any  indebtedness for borrowed money or guarantee
          any  such  indebtedness  or  issue  or sell  any  debt  securities  or
          guarantee any debt  securities of others;  (g) Leases.  Enter into any
          operating lease in excess of $24,000 per annum;

     (h)  Payment  of  Obligations.  Pay,  discharge  or satisfy in an amount in
          excess of $10,000 in any one case or  $100,000 in the  aggregate,  any
          claim,  liability  or  obligation  (absolute,   accrued,  asserted  or
          unasserted,  contingent  or  otherwise)  arising  other  than  in  the
          ordinary  course of  business,  other than the  payment,  discharge or
          satisfaction  of  liabilities  reflected  or  reserved  against in the
          financial  statements of  VerticalBuyer  or its subsidiary,  Lightseek
          Limited;

     (i)  Capital Expenditures. Make any capital expenditures, capital additions
          or capital  improvements except in the ordinary course of business and
          consistent with past practice;

     (j)  Insurance.  Materially  reduce  the amount of any  material  insurance
          coverage  provided by insurance  policies  whether  existing or placed
          during the term of this Agreement;

     (k)  Termination  or Waiver.  Terminate  or waive any right of  substantial
          value, other than in the ordinary course of business;

     (l)  Employee Benefit Plans;  New Hires; Pay Increases.  Adopt or amend any
          employee  benefit or stock  purchase or option  plan,  or hire any new
          officer level employee,  or increase the salaries or wage rates of its
          employees except in the ordinary course of business in accordance with
          its standard past practice;

     (m)  Severance Arrangements.  Grant any severance or termination pay (i) to
          any  director  or  officer  or (ii) to any other  employee  except (A)
          payments made pursuant to written  agreements  outstanding on the date
          hereof or (B) grants which are made in the ordinary course of business
          in accordance with its standard past practice;

     (n)  Lawsuits. Commence a lawsuit other than (i) for the routine collection
          of bills,  (ii) in such cases where it in good faith  determines  that
          failure to commence suit would result in the material  impairment of a
          valuable aspect of its business;

     (o)  Acquisitions.  Acquire or agree to acquire by merging or consolidating
          with, or by  purchasing a substantial  portion of the assets of, or by
          any  other  manner,  any  business  or any  corporation,  partnership,
          association or other business  organization  or division  thereof,  or
          otherwise  acquire or agree to acquire any assets which are  material,
          individually    or   in    the    aggregate,    to   its    and    its
          parent's/subsidiaries' business, taken as a whole;

                                       2
<PAGE>

     (p)  Taxes.  Other than in the ordinary course of business,  make or change
          any  material  election  in  respect  of taxes,  adopt or  change  any
          accounting method in respect of Taxes, file any material tax return or
          any  amendment  to a  material  tax  return,  enter  into any  closing
          agreement,  settle  any  material  claim or  assessment  in respect of
          Taxes, or consent to any extension or waiver of the limitation  period
          applicable to any material claim or assessment in respect of taxes;

     (r)  Revaluation.  Revalue any of its assets,  including without limitation
          writing  down the value of  inventory or writing off notes or accounts
          receivable other than in the ordinary course of business; or

     (s)  Other. Take or agree in writing or otherwise to take, any action which
          would cause a material  breach of its  representations  or  warranties
          contained in any agreement or prevent it from materially performing or
          cause it not to materially perform its covenants thereunder.

     3.  Assignment;  Binding  Effect.  Subject to  termination  as  provided in
Section 7, this Agreement  shall be binding on the Parties and their  respective
legal  representatives,  successors  and assigns and on the  transferees  of any
Shares now owned or hereafter acquired by them.

     4. Entire Agreement;  Waiver.  This Agreement  contains the sole and entire
understanding of the Parties with respect to its subject matter.  This Agreement
may not be changed or  terminated or any  performance  or condition  waived,  in
whole or in part, except by agreement in writing signed by all of the Parties.

     5.  Counterparts.   This  Agreement  may  be  executed  in  more  than  one
counterpart,  each of  which  shall  be  deemed  to be an  original  and  which,
together, shall constitute one and the same instrument.

     6.  Applicable  Law. This Agreement shall be governed by, and construed and
enforced  in  accordance  with,  the  substantive  laws of The  Commonwealth  of
Massachusetts, without regard to its principles of conflicts of laws.

     7.  Legend.  Each  certificate  for Shares  shall bear a legend  stating in
substance as follows:

     "The  rights of any  holders of these  shares are  subject to the terms and
     provisions of a Voting  Agreement  dated March 2, 2000 among  VerticalBuyer
     and certain shareholders of VerticalBuyer.  Copies of such agreement may be
     obtained   without  charge  upon  written   request  to  the  secretary  of
     VerticalBuyer."

     8.  Termination.  This Agreement shall terminate and be of no further force
and effect upon the exercise  redemption or expiration of all of the outstanding
Common Stock  Purchase  Warrants of  VerticalBuyer  issued to CSPI and dated the
date hereof  providing for the  purchase,  subject to  adjustment,  of 3,000,000
shares of VerticalBuyer's Common Stock.

     IN WITNESS  WHEREOF,  this  Agreement has been duly executed as of the date
first above written.

                                   VERTICALBUYER, INC.

                                   By: /s/Tim Rosen
                                       ---------------------
                                         Tim Rosen,
                                         President

                                            CSPI, INC.

                                   By: /s/Alexander Lupinetti
                                       ------------------------
                                         Alexander Lupinetti,
                                         Chief Executive Officer

                           /s/Tim Rosen                /s/Leslie Kent
                           ---------------------       -----------------
                              Tim Rosen               Leslie Kent

                                       3
<PAGE>