Document:

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                                                                   Exhibit 10.50

                         COMMON STOCK PURCHASE AGREEMENT

                  This COMMON STOCK PURCHASE AGREEMENT (this "Agreement") is
dated as of May 10, 2001 by and between StemCells, Inc., a Delaware
corporation (the "Company") and Sativum Investments Limited (the
"Purchaser"), a British Virgin Islands corporation.

                  WHEREAS, the parties desire that, upon the terms and
subject to the conditions contained herein, the Company shall issue and sell
to Purchaser from time to time as provided herein, and Purchaser shall
purchase, up to $30,000,000 of Common Stock and the Warrant; and

                  WHEREAS, such investments will be made by the Purchaser as
statutory underwriter of a registered indirect primary offering of such
Common Stock by the Company.

                  NOW, THEREFORE, in consideration of the foregoing premises,
and the promises and covenants herein contained, the receipt and sufficiency
of which are hereby acknowledged by the parties hereto, the parties,
intending to be legally bound, hereby agree as follows:

                                    ARTICLE 1

                        PURCHASE AND SALE OF COMMON STOCK

                  Section 1.1. PURCHASE AND SALE OF STOCK. Subject to the
terms and conditions of this Agreement, the Company may sell and issue to the
Purchaser and the Purchaser shall be obligated to purchase from the Company,
up to an aggregate of $30,000,000 of Common Stock (the "Commitment Amount")
and the Warrant, subject to the terms herein.

                  Section 1.2. PURCHASE PRICE AND INITIAL CLOSING. The
Company agrees to issue and sell to the Purchaser and, in consideration of
and in express reliance upon the representations, warranties, covenants,
terms and conditions of this Agreement, the Purchaser agrees to purchase that
number of the Shares to be issued in connection with each Draw Down. The
delivery of executed documents under this Agreement and the other agreements
referred to herein and the payment of the fees set forth in Article I of the
Escrow Agreement, attached as EXHIBIT B hereto, (the "Initial Closing") shall
take place at the offices of Epstein Becker & Green, P.C., 250 Park Avenue,
New York, New York 10177 (i) within five (5) days from the date hereof, or
(ii) such other time and place or on such date as the Purchaser and the
Company may agree upon (the "Initial Closing Date"). Each party shall deliver
all documents, instruments and writings required to be delivered by such
party pursuant to this Agreement at or prior to the Initial Closing.

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                  Section 1.3. LIQUIDATED DAMAGES. The parties hereto
acknowledge and agree that the sums payable pursuant to this Agreement for
late delivery of the Draw Down Shares and the Registration Rights Agreement
for a suspension of the Registration Statement or the Purchaser's right to
resell the Draw Down Shares thereunder shall constitute liquidated damages
and not penalties. The parties further acknowledge that (a) the amount of
loss or damages likely to be incurred is incapable or is difficult to
precisely estimate, (b) the amount specified in such provisions bear a
reasonable proportion and are not plainly or grossly disproportionate to the
probable loss likely to be incurred by the Purchaser in connection with the
failure of the Company to deliver the Draw Down Shares in a timely manner or
the suspension of the Purchaser's rights to resell the Draw Down Shares under
the Registration Statement, and (c) the parties are sophisticated businesses
and have been represented by sophisticated and able legal and financial
counsel and negotiated this Agreement at arm's length.

                                    ARTICLE 2

                         REPRESENTATIONS AND WARRANTIES

                  Section 2.1. REPRESENTATION AND WARRANTIES OF THE COMPANY.
The Company hereby represents and warrants to the Purchaser as follows,
except as set forth in the SEC Documents or on the Disclosure Schedule
prepared by the Company and attached hereto, or as contemplated by this
Agreement:

                           (a) ORGANIZATION, GOOD STANDING AND POWER. The
         Company is a corporation duly incorporated validly existing and in good
         standing under the laws of Delaware and has all requisite corporate
         authority to own, lease and operate its properties and assets and to
         carry on its business as now being conducted. The Company does not have
         any subsidiaries and does not own more than fifty percent (50%) of or
         control any other business entity except as set forth in the SEC
         Documents. The Company is duly qualified to do business and is in good
         standing as a foreign corporation in every jurisdiction in which the
         nature of the business conducted or property owned by it makes such
         qualification necessary, other than those in which the failure so to
         qualify would not have a Material Adverse Effect.

                           (b) AUTHORIZATION, ENFORCEMENT. (i) The Company has
         the requisite corporate power and corporate authority to enter into and
         perform its obligations under the Transaction Documents and to issue
         the Draw Down Shares pursuant to their respective terms, (ii) the
         execution and delivery of the Transaction Documents by the Company and
         the consummation by it of the transactions contemplated hereby and
         thereby have been duly authorized by all necessary corporate action and
         no further consent or authorization of the Company or its Board of
         Directors or stockholders is required, and (iii) the Transaction
         Documents have been duly executed and delivered by the Company and at
         the Initial Closing shall constitute valid and binding obligations of
         the Company enforceable against the Company in accordance with their
         terms, except as such enforceability may be limited by applicable
         bankruptcy, insolvency, reorganization, moratorium, liquidation,
         conservatorship, receivership or similar laws relating to, or

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         affecting generally the enforcement of, creditors' rights and
         remedies or by other equitable principles of general application.

                           (c) CAPITALIZATION. As of the date hereof, the
         authorized capital stock of the Company consists of 45,000,000 shares
         of Common Stock of which 21,470,385 shares are issued and outstanding
         and 1,000,000 shares of Convertible Preferred Stock of which 1,500 are
         issued and outstanding. All of the outstanding shares of the Company's
         Common Stock have been duly and validly authorized and are fully paid
         and non-assessable except as set forth in the SEC Documents. No shares
         of Common Stock are entitled to preemptive rights or registration
         rights and there are no outstanding options, warrants, scrip, rights to
         subscribe to, calls or commitments of any character whatsoever relating
         to, or securities or rights convertible into, any shares of capital
         stock of the Company. There are no contracts, commitments,
         understandings, or arrangements by which the Company is or may become
         bound to issue additional shares of the capital stock of the Company or
         options, securities or rights convertible into shares of capital stock
         of the Company. The Company is not a party to any agreement granting
         registration rights to any person with respect to any of its equity or
         debt securities. The Company is not a party to, and it has no knowledge
         of, any agreement restricting the voting or transfer of any shares of
         the capital stock of the Company. The Company has made available to the
         Purchaser true and correct copies of the Company's articles or
         certificate of incorporation as in effect on the date hereof (the
         "Charter"), and the Company's bylaws as in effect on the date hereof
         (the "Bylaws"). The Company has not received any notice from the
         Principal Market questioning or threatening the continued inclusion of
         the Common Stock on such market.

                           (d) ISSUANCE OF SHARES. The Warrant Shares to be
         issued under this Agreement have been duly authorized by all necessary
         corporate action and, when paid for and issued in accordance with the
         terms hereof and the Warrant, the Warrant Shares shall be validly
         issued and outstanding, fully paid and non-assessable, and the
         Purchaser shall be entitled to all rights accorded to a holder of
         Common Stock.

                           (e) NO CONFLICTS. The execution, delivery and
         performance of this Agreement by the Company and the consummation by
         the Company of the transactions contemplated herein do not and will not
         (i) violate any provision of the Company's Charter or Bylaws, (ii)
         conflict with, or constitute a default (or an event which with notice
         or lapse of time or both would become a default) under, or give to
         others any rights of termination, amendment, acceleration or
         cancellation of, any agreement, mortgage, deed of trust, indenture,
         note, bond, license, lease agreement, instrument or obligation to which
         the Company is a party, (iii) create or impose a lien, charge or
         encumbrance on any property of the Company under any agreement or any
         commitment to which the Company is a party or by which the Company is
         bound or by which any of its respective properties or assets are bound,
         or (iv) result in a violation of any federal, state, local or other
         foreign statute, rule, regulation, order, judgment or decree (including
         any federal or state securities laws and regulations) applicable to the
         Company or any of its subsidiaries or by which any property or asset of
         the Company or any of its subsidiaries are bound or affected, except,
         in all cases, for such conflicts, defaults, termination, amendments,

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         accelerations, cancellations and violations as would not reasonably be
         expected, individually or in the aggregate, to have a Material Adverse
         Effect. The business of the Company and its subsidiaries is not being
         conducted in violation of any laws, ordinances or regulations of any
         governmental entity, except for violations which singularly or in the
         aggregate do not and will not have a Material Adverse Effect. The
         Company is not required under any federal, state or local law, rule or
         regulation to obtain any consent, authorization or order of, or make
         any filing or registration with, any court or governmental agency in
         order for it to execute, deliver or perform any of its obligations
         under this Agreement, or issue and sell the Shares in accordance with
         the terms hereof (other than any filings which may be required to be
         made by the Company with the SEC or state securities administrators and
         any registration statement which may be filed pursuant hereto);
         PROVIDED, HOWEVER, that for purpose of the representations made in this
         sentence, the Company is assuming and relying upon the accuracy of the
         relevant representations and agreements of the Purchaser herein.

                           (f) SEC DOCUMENTS, FINANCIAL STATEMENTS. The Common
         Stock of the Company is registered pursuant to Section 12(g) of the
         Exchange Act, and, the Company is current with all reports, schedules,
         forms, statements and other documents required to be filed by it with
         the SEC pursuant to the reporting requirements of the Exchange Act,
         including material filed pursuant to Section 13(a) or 15(d) of the
         Exchange Act. The Company has delivered or made available to the
         Purchaser, through the EDGAR system or otherwise, true and complete
         copies of the SEC Documents filed with the SEC since December 31, 1998.
         The Company has not provided to the Purchaser any information which,
         according to applicable law, rule or regulation, should have been
         disclosed publicly by the Company but which has not been so disclosed,
         other than with respect to the transactions contemplated by this
         Agreement. As of their respective filing dates, the SEC Documents
         complied in all material respects with the requirements of the Exchange
         Act or the Securities Act, as applicable, and the rules and regulations
         of the SEC promulgated thereunder applicable to such documents, and, as
         of their respective filing dates, none of the SEC Documents contained
         any untrue statement of a material fact or omitted to state a material
         fact required to be stated therein or necessary in order to make the
         statements therein, in light of the circumstances under which they were
         made, not misleading. The financial statements of the Company included
         in the SEC Documents comply as to form in all material respects with
         applicable accounting requirements under GAAP and the published rules
         and regulations of the SEC or other applicable rules and regulations
         with respect thereto. Such financial statements have been prepared in
         accordance with GAAP applied on a consistent basis during the periods
         involved (except (i) as may be otherwise indicated in such financial
         statements or the notes thereto or (ii) in the case of unaudited
         interim statements, to the extent they may not include footnotes or may
         be condensed or summary statements), and fairly present in all material
         respects the financial position of the Company and its subsidiaries as
         of the dates thereof and the results of operations and cash flows for
         the periods then ended (subject, in the case of unaudited statements,
         to normal year-end audit adjustments).

                           (g) SUBSIDIARIES. The SEC Documents or the Disclosure
         Schedule attached hereto sets forth each subsidiary of the Company,
         showing the jurisdiction of its

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         incorporation or organization and showing the percentage of
         the Company's ownership of the outstanding stock or other interests
         of such subsidiary. For the purposes of this Agreement, "subsidiary"
         shall mean any corporation or other entity of which at least a
         majority of the securities or other ownership interests having
         ordinary voting power (absolutely or contingently) for the election
         of directors or other persons performing similar functions are at
         the time owned directly or indirectly by the Company and/or any of
         its other subsidiaries. All of the issued and outstanding shares of
         capital stock of each subsidiary have been duly authorized and
         validly issued, and are fully paid and non-assessable. There are no
         outstanding preemptive, conversion or other rights, options,
         warrants or agreements granted or issued by or binding upon any
         subsidiary for the purchase or acquisition of any shares of capital
         stock of any subsidiary or any other securities convertible into,
         exchangeable for or evidencing the rights to subscribe for any
         shares of such capital stock. Neither the Company nor any subsidiary
         is subject to any obligation (contingent or otherwise) to repurchase
         or otherwise acquire or retire any shares of the capital stock of
         any subsidiary or any convertible securities, rights, warrants or
         options of the type described in the preceding sentence. Neither the
         Company nor any subsidiary is a party to, nor has any knowledge of,
         any agreement restricting the voting or transfer of any shares of
         the capital stock of any subsidiary.

                           (h) NO MATERIAL ADVERSE EFFECT. Since the date of the
         financial statement contained in the most recently filed Form 10-Q (or
         10-QSB) or Form 10-K (or 10-KSB), whichever is most current, no
         Material Adverse Effect has occurred or exists with respect to the
         Company, except as disclosed in the SEC Documents or on the Disclosure
         Schedule attached hereto.

                           (i) NO UNDISCLOSED LIABILITIES. Neither the Company
         nor any of its subsidiaries has any liabilities, obligations, claims or
         losses (whether liquidated or unliquidated, secured or unsecured,
         absolute, accrued, contingent or otherwise) that would be required to
         be disclosed on a balance sheet of the Company or any subsidiary
         (including the notes thereto) in conformity with GAAP which are not
         disclosed in the SEC Documents, other than those incurred in the
         ordinary course of the Company's or its subsidiaries' respective
         businesses since such date or which, individually or in the aggregate,
         do not or would not have a Material Adverse Effect on the Company or
         its subsidiaries.

                           (j) NO UNDISCLOSED EVENTS OR CIRCUMSTANCES. Since the
         date of the financial statement contained in the most recently filed
         Form 10- Q (or 10-QSB) or Form 10-K (or 10-KSB), whichever is most
         current, no event or circumstance has occurred or exists with respect
         to the Company or its businesses, properties, prospects, operations or
         financial condition, that, under applicable law, rule or regulation,
         requires public disclosure or announcement prior to the date hereof by
         the Company but which has not been so publicly announced or disclosed
         in the SEC Documents.

                           (k) INDEBTEDNESS. The SEC Documents (including the
         financial statements included therein) or the Disclosure Schedule
         attached hereto sets forth as of the date hereof all outstanding
         secured and unsecured Indebtedness of the Company or

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         any subsidiary, or for which the Company or any subsidiary
         has commitments. For the purposes of this Agreement, "Indebtedness"
         shall mean (A) any liabilities for borrowed money in excess of
         $500,000 (other than trade accounts payable incurred in the ordinary
         course of business), (B) all guaranties, endorsements and contingent
         obligations in respect of Indebtedness of others, whether or not the
         same are or should be reflected in the Company's balance sheet (or
         the notes thereto), except guaranties by endorsement of negotiable
         instruments for deposit or collection or similar transactions in the
         ordinary course of business; and (C) any lease payments with a
         present value in excess of $500,000 due under leases required to be
         capitalized in accordance with GAAP. Neither the Company nor any
         subsidiary is in default with respect to any Indebtedness.

                           (l) TITLE TO ASSETS. Each of the Company and the
         subsidiaries has good and marketable title to all of its real and
         personal property reflected in the SEC Documents, free of any
         mortgages, pledges, charges, liens, security interests or other
         encumbrances, except such that do not cause a Material Adverse Effect.
         All real property leases of the Company and each of its subsidiaries
         are valid and subsisting and in full force and effect.

                           (m) ACTIONS PENDING. There is no action, suit, claim,
         investigation or proceeding pending or, to the knowledge of the
         Company, threatened against the Company or any subsidiary which
         questions the validity of this Agreement or the transactions
         contemplated hereby or any action taken or to be taken pursuant hereto
         or thereto. There is no action, suit, claim, investigation or
         proceeding pending or, to the knowledge of the Company, threatened,
         against or involving the Company, any subsidiary or any of their
         respective properties or assets, which action, suit, claim,
         investigation or proceeding would reasonably be expected to have a
         Material Adverse Effect. There are no outstanding orders, judgments,
         injunctions, awards or decrees of any court, arbitrator or governmental
         or regulatory body against the Company or any subsidiary except those
         orders, judgments, injunctions, awards or decrees which would not
         reasonably be expected to have a Material Adverse Effect.

                           (n) COMPLIANCE WITH LAW. The Company and each of its
         subsidiaries have all franchises, permits, licenses, consents and other
         governmental or regulatory authorizations and approvals necessary for
         the conduct of their respective businesses as now being conducted by
         them unless the failure to possess such franchises, permits, licenses,
         consents and other governmental or regulatory authorizations and
         approvals, individually or in the aggregate, could not reasonably be
         expected to have a Material Adverse Effect.

                           (o) TAXES. The Company and each subsidiary has filed
         all Tax Returns which it is required to file under applicable laws;
         except as set forth in the SEC Documents the Company and each
         subsidiary have paid, or had paid on its or their behalf, all Taxes
         shown as due on such Tax Returns and has withheld and paid over to the
         appropriate taxing authorities all Taxes which it is required to
         withhold from amounts paid or owing to any employee, stockholder,
         creditor or other third parties; and since December 31, 1999, the
         charges, accruals and reserves for Taxes with respect to the

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         Company (including any provisions for deferred income taxes)
         reflected on the books of the Company are to its knowledge adequate
         to cover any Tax liabilities of the Company if its current tax year
         were treated as ending on the date hereof.

                           No claim has been made by a taxing authority in a
         jurisdiction where the Company does not file tax returns that the
         Company or any subsidiary is or may be subject to taxation by that
         jurisdiction. Except as set forth in the SEC Documents, there are no
         foreign, federal, state or local tax audits or administrative or
         judicial proceedings pending or being conducted with respect to the
         Company or any subsidiary.

                           The Company has not made an election under Section
         341 (f) of the Internal Revenue Code. The Company is not liable for
         the Taxes of another person that is not a subsidiary of the Company
         under (A) Treas. Reg. Section 1.1502-6 (or comparable provisions of
         state, local or foreign law), (B) as a transferee or successor, (C)
         by contract or indemnity or (D) otherwise.

                           For purposes of this Section 2.1(o):

                           "IRS" means the United States Internal Revenue
                           Service.

                           "TAX" or "TAXES" means federal, state, county, local,
                           foreign, or other income, gross receipts, ad valorem,
                           franchise, profits, sales or use, transfer,
                           registration, excise, utility, environmental,
                           communications, real or personal property, capital
                           stock, license, payroll, wage or other withholding,
                           employment, social security, severance, stamp,
                           occupation, alternative or add-on minimum, estimated
                           and similar taxes (including, without limitation,
                           deficiencies, penalties, additions to tax, and
                           interest attributable thereto) whether disputed or
                           not.

                           "TAX RETURN" means any return, information report or
                           filing with respect to Taxes, including any schedules
                           attached thereto and including any amendment thereof.

                           (p) CERTAIN FEES.  Except for the fees paid to
         Pacific Crest Securities Inc. pursuant to the Engagement Letter, no
         brokers, finders or financial advisory fees or commissions will be
         payable by the Company or any subsidiary with respect to the
         transactions contemplated by this Agreement.

                           (q) OPERATION OF BUSINESS. The Company and each of
         the subsidiaries owns or possesses all patents, trademarks, service
         marks, trade names, copyrights, licenses and authorizations as set
         forth in the SEC Documents or the Disclosure Schedule attached hereto,
         and all rights with respect to the foregoing, which to its knowledge
         would be reasonably necessary for the conduct of its business as now
         conducted without any conflict with the rights of others.

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                           (r) BOOKS AND RECORDS.  The records and documents of
         the Company and its subsidiaries accurately reflect in all material
         respects the information relating to the business of the Company and
         the subsidiaries contained therein.

                           (s) MATERIAL AGREEMENTS. The Company and each of its
         subsidiaries has in all material respects performed all the obligations
         required to be performed by them to date under the foregoing
         agreements, have received no notice of default and, to the best of the
         Company's knowledge are not in default under any Material Agreement now
         in effect, the result of which would cause a Material Adverse Effect.
         No written or oral contract, instrument, agreement, commitment,
         obligation, plan or arrangement of the Company or of any subsidiary
         limits or shall limit the payment of dividends on the Company's Common
         Stock.

                           (t) TRANSACTIONS WITH AFFILIATES. There are no loans,
         leases, agreements, contracts, royalty agreements, management contracts
         or arrangements or other continuing transactions exceeding $100,000
         between (A) the Company, any subsidiary or any of their respective
         customers or suppliers on the one hand, and (B) on the other hand, any
         officer, employee, consultant or director of the Company, or any of its
         subsidiaries, or any person owning 5% or more of the capital stock of
         the Company or any subsidiary or any member of the immediate family of
         such officer, employee, consultant, director or stockholder or any
         corporation or other entity controlled by such officer, employee,
         consultant, director or stockholder, or a member of the immediate
         family of such officer, employee, consultant, director or stockholder.

                           (u) SECURITIES LAWS. The Company has complied and
         will comply with all applicable federal and state securities laws in
         connection with the offer, issuance and sale of the Shares hereunder.
         Neither the Company nor anyone acting on its behalf, directly or
         indirectly, has or will sell, offer to sell or solicit offers to buy
         the Shares or similar securities to, or solicit offers with respect
         thereto from, or enter into any preliminary conversations or
         negotiations relating thereto with, any person (other than the
         Purchaser), so as to bring the issuance and sale of the Shares under
         the registration provisions of the Securities Act and applicable state
         securities laws. Neither the Company nor any of its affiliates, nor any
         person acting on its or their behalf, has engaged in any form of
         general solicitation or general advertising (within the meaning of
         Regulation D under the Securities Act) in connection with the offer or
         sale of the Shares.

                           (v) EMPLOYEES. Neither the Company nor any subsidiary
         has any collective bargaining arrangements or agreements covering any
         of its employees. Neither the Company nor any subsidiary is in breach
         of any employment contract, agreement regarding proprietary
         information, noncompetition agreement, nonsolicitation agreement,
         confidentiality agreement, or any other similar contract or restrictive
         covenant, relating to the right of any officer to be employed or
         engaged by the Company or such subsidiary. Since the date of the
         December 31, 2000 Form 10-K (or 10-KSB), no officer, consultant or key
         employee of the Company or any subsidiary whose termination, either
         individually or in the aggregate, could have a Material Adverse Effect,
         has terminated or, to the

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         knowledge of the Company, has any present intention of terminating
         his or her employment or engagement with the Company or any
         subsidiary.

                           (w) ABSENCE OF CERTAIN DEVELOPMENTS. Since the date
         of the financial statement contained in the most recently filed Form
         10-Q (or 10-QSB) or Form 10-K (or 10KSB), whichever is most current,
         neither the Company nor any subsidiary has done any of the following,
         if such occurrences could reasonably be expected to have a Material
         Adverse Effect:

                                    (i) issued any stock, bonds or other
                  corporate securities or any rights, options or warrants with
                  respect thereto, except for issuances of shares of stock
                  pursuant to options or warrants outstanding on the date hereof
                  or issuance of stock options pursuant to a stock option plan;

                                    (ii) borrowed any amount or incurred or
                  become subject to any liabilities (absolute or contingent)
                  except amounts borrowed or liabilities incurred in the
                  ordinary course of business;

                                    (iii) discharged or satisfied any lien or
                  encumbrance or paid any obligation or liability (absolute or
                  contingent), other than liabilities paid in the ordinary
                  course of business;

                                    (iv) declared or made any payment or
                  distribution of cash or other property to stockholders with
                  respect to its stock, or purchased or redeemed, or made any
                  agreements so to purchase or redeem, any shares of its capital
                  stock;

                                    (v) sold, assigned or transferred any other
                  tangible assets, or canceled any debts or claims, except in
                  the ordinary course of business;

                                    (vi) sold, assigned or transferred any
                  patent rights, trademarks, trade names, copyrights, trade
                  secrets or other intangible assets or intellectual property
                  rights, or disclosed any proprietary confidential information
                  to any person except to customers in the ordinary course of
                  business, to persons bound by agreements restricting
                  disclosure of such proprietary confidential information or to
                  the Purchaser or its representatives;

                                    (vii) made any changes in employee
                  compensation except in the ordinary course of business and
                  consistent with past practices;

                                    (viii) made capital expenditures or
                  commitments therefor that aggregate in excess of $500,000;

                                    (ix) entered into any other material
                  transaction required to be disclosed in the SEC Documents,
                  whether or not in the ordinary course of business;

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                                    (x) suffered any material damage,
                  destruction or casualty loss, whether or not covered by
                  insurance;

                                    (xi) experienced any material problems with
                  labor or management in connection with the terms and
                  conditions of their employment; or

                                    (xii) effected any two or more events of the
                  foregoing kind which in the aggregate would be material to the
                  Company or its subsidiaries.

                           (x) GOVERNMENTAL APPROVALS. Except for the filing of
         any notice prior or subsequent to any Settlement Date that may be
         required under applicable federal or state securities laws (which if
         required, shall be filed on a timely basis), including the filing of a
         registration statement or post-effective amendment pursuant to this
         Agreement, no authorization, consent, approval, license, exemption of,
         filing or registration with any court or governmental department,
         commission, board, bureau, agency or instrumentality, domestic or
         foreign, is or will be necessary for, or in connection with, the
         delivery of the Shares, or for the performance by the Company of its
         obligations under this Agreement.

                           (aa) ACKNOWLEDGMENT REGARDING PURCHASER'S PURCHASE OF
         SHARES. Company acknowledges and agrees that Purchaser is acting solely
         in the capacity of arm's length purchaser with respect to this
         Agreement and the transactions contemplated hereunder. The Company
         further acknowledges that the Purchaser is not acting as a financial
         advisor or fiduciary of the Company (or in any similar capacity) with
         respect to this Agreement and the transactions contemplated hereunder.
         The Company further represents to the Purchaser that the Company's
         decision to enter into this Agreement has been based solely on (a) the
         Purchaser's representations and warranties in Section 2.2, and (b) the
         independent evaluation by the Company and its own representatives and
         counsel.

                  Section 2.2. REPRESENTATIONS AND WARRANTIES OF THE
PURCHASER. The Purchaser hereby makes the following representations and
warranties to the Company:

                           (a) ORGANIZATION AND STANDING OF THE PURCHASER.
         The Purchaser is a corporation duly incorporated, validly existing
         and in good standing under the laws of the British Virgin Islands.

                           (b) AUTHORIZATION AND POWER. The Purchaser has the
         requisite power and authority to enter into and perform the Transaction
         Documents and to purchase the Shares. The execution, delivery and
         performance of the Transaction Documents by Purchaser and the
         consummation by it of the transactions contemplated hereby have been
         duly authorized by all necessary corporate action and at the Initial
         Closing shall constitute valid and binding obligations of the Purchaser
         enforceable against the Purchaser in accordance with their terms,
         except as such enforceability may be limited by applicable bankruptcy,
         insolvency, reorganization, moratorium, liquidation, conservatorship,
         receivership or similar laws relating to, or affecting generally the
         enforcement of, creditors' rights and remedies or by other equitable
         principles of general application

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                           (c) NO CONFLICTS. The execution, delivery and
         performance of this Agreement and the consummation by the Purchaser of
         the transactions contemplated hereby or relating hereto do not and will
         not (i) result in a violation of the Purchaser's charter documents or
         bylaws or (ii) conflict with, or constitute a default (or an event
         which with notice or lapse of time or both would become a default)
         under, or give to others any rights of termination, amendment,
         acceleration or cancellation of any agreement, indenture or instrument
         to which the Purchaser is a party, or result in a violation of any law,
         rule, or regulation, or any order, judgment or decree of any court or
         governmental agency applicable to the Purchaser or its properties
         (except for such conflicts, defaults and violations as would not,
         individually or in the aggregate, have a Material Adverse Effect on
         Purchaser). The Purchaser is not required to obtain any consent,
         authorization or order of, or make any filing or registration with, any
         court or governmental agency in order for it to execute, deliver or
         perform any of its obligations under this Agreement or to purchase the
         Shares in accordance with the terms hereof.

                           (d) FINANCIAL RISKS. The Purchaser acknowledges that
         it is able to bear the financial risks associated with an investment in
         the Shares and that it has been given full access to such records of
         the Company and the subsidiaries and to the officers of the Company and
         the subsidiaries as it has deemed necessary or appropriate to conduct
         its due diligence investigation. The Purchaser is capable of evaluating
         the risks and merits of an investment in the Shares by virtue of its
         experience as an investor and its knowledge, experience, and
         sophistication in financial and business matters and the Purchaser is
         capable of bearing the entire loss of its investment in the Shares.

                           (e) ACCREDITED INVESTOR. The Purchaser is an
         "accredited investor" as defined in Rule 501 of Regulation D
         promulgated under the Securities Act.

                           (f) GENERAL. The Purchaser understands that the
         Company is relying upon the truth and accuracy of the representations,
         warranties, agreements, acknowledgments and understandings of the
         Purchaser set forth herein in order to determine the suitability of the
         Purchaser to acquire the Shares.

                                    ARTICLE 3

                                    COVENANTS

                  The Company covenants with the Purchaser as follows:

                  Section 3.1. THE SHARES. As of the date of each applicable
Draw Down, the Company will have authorized and reserved, free of preemptive
rights, a sufficient number of authorized but unissued shares of its Common
Stock to cover the Draw Down Shares to be issued in connection with such Draw
Down requested under this Agreement. The Draw Down Shares to be issued under
this Agreement, when paid for and issued in accordance with the terms hereof,
shall be duly and validly issued and outstanding, fully paid and
non-assessable, and the

                                      11

<PAGE>

Purchaser shall be entitled to all rights accorded to a holder of Common
Stock. Anything in this Agreement to the contrary notwithstanding, (i) at no
time will the Company request a Draw Down which would result in the issuance
of an aggregate number of shares of Common Stock pursuant to this Agreement
which exceeds 19.9% of the number of shares of Common Stock issued and
outstanding on the Initial Closing Date without obtaining stockholder
approval of such excess issuance, or such other amount as would require
stockholder approval under rules of the Principal Market or otherwise without
obtaining stockholder approval of such excess issuance, and (ii) the Company
may not make a Draw Down to the extent that, after such purchase by the
Purchaser, the sum of the number of shares of Common Stock beneficially owned
by the Purchaser and its affiliates would result in beneficial ownership by
the Purchaser and its affiliates of more than 9.9% of the then outstanding
shares of Common Stock. For purposes of the immediately preceding sentence,
beneficial ownership shall be determined in accordance with Section 13(d) of
the Exchange Act.

                  Section 3.2. SECURITIES COMPLIANCE. If applicable, the
Company shall notify the Principal Market, in accordance with its rules and
regulations, of the transactions contemplated by this Agreement, and shall
take all other necessary action and proceedings as may be required and
permitted by applicable law, rule and regulation, for the legal and valid
issuance of the Shares and the Warrant to the Purchaser or subsequent holders.

                  Section 3.3. REGISTRATION AND LISTING. The Company will
cause its Common Stock to continue to be registered under Sections 12(b) or
12(g) of the Exchange Act, will comply in all material respects with its
reporting and filing obligations under the Exchange Act, will comply with all
requirements related to any registration statement filed pursuant to this
Agreement, and will not take any action or file any document (whether or not
permitted by the Securities Act or the Exchange Act or the rules promulgated
thereunder) to terminate or suspend such registration or to terminate or
suspend its reporting and filing obligations under the Exchange Act or
Securities Act, except as permitted herein. The Company will take all action
necessary to continue the listing or trading of its Common Stock on the
Principal Market and will comply in all respects with the Company's
reporting, filing and other obligations under the bylaws or rules of the
Principal Market and shall provide the Purchaser with copies of any
correspondence to or from such Principal Market which questions or threatens
delisting of the Common Stock, within three (3) Trading Days of the Company's
receipt thereof, until the Purchaser has disposed of all of the Shares.

                  Section 3.4. ESCROW ARRANGEMENT. The Company and the
Purchaser shall enter into an escrow arrangement with Epstein Becker & Green,
P.C. (the "Escrow Agent") in the form of EXHIBIT B hereto respecting payment
against delivery of the Shares.

                  Section 3.5. REGISTRATION RIGHTS AGREEMENT. The Company and
the Purchaser shall enter into the Registration Rights Agreement in the Form
of EXHIBIT A hereto. Before the Purchaser shall be obligated to accept a Draw
Down request from the Company, the Company shall have caused a sufficient
number of shares of Common Stock to be registered to cover the Shares to be
issued in connection with such Draw Down.

                                      12

<PAGE>

                  Section 3.6. ACCURACY OF REGISTRATION STATEMENT.On each
Settlement Date, the Registration Statement and the prospectus therein (a)
shall not contain any untrue statement of a material fact or omit to state
any material fact to be required to be stated therein or necessary in order
to make the statements therein not misleading in light of the circumstances
under which they were made; and (b) on such Settlement Date or date of filing
of the Registration Statement and the prospectus therein will not include any
untrue statement of a material fact or omit to state a material fact
necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading; PROVIDED, HOWEVER,
the Company makes no representations or warranties as to the information
contained in or omitted from the Registration Statement and the prospectus
therein in reliance upon and in conformity with the information furnished in
writing to the Company by the Purchaser specifically for inclusion in the
Registration Statement and the prospectus therein.

                  Section 3.7. COMPLIANCE WITH LAWS. The Company shall
materially comply, and cause each subsidiary to materially comply, with all
applicable state, federal and Principal Market laws, rules, regulations and
orders, noncompliance with which could have a Material Adverse Effect.

                  Section 3.8. OTHER AGREEMENTS. The Company shall not enter
into any agreement the terms of which would restrict the ability of the
Company to perform its obligations under this Agreement.

                  Section 3.9. NOTICE OF CERTAIN EVENTS AFFECTING
REGISTRATION; SUSPENSION OF RIGHT TO REQUEST A DRAW DOWN. SUBJECT TO
APPLICABLE LAWS, RULES, REGULATIONS AND ORDERS, THE COMPANY WILL PROMPTLY
NOTIFY THE PURCHASER IN WRITING UPON THE OCCURRENCE OF ANY OF THE FOLLOWING
EVENTS IN RESPECT OF THE REGISTRATION STATEMENT OR RELATED PROSPECTUS IN
RESPECT OF THE SHARES: (i) receipt of any request for additional information
from the SEC or any other federal or state governmental authority during the
period of effectiveness of the Registration Statement the response to which
would require any amendments or supplements to the Registration Statement or
related prospectus; (ii) the issuance by the SEC or any other federal or
state governmental authority of any stop order suspending the effectiveness
of the Registration Statement or the initiation of any proceedings for that
purpose; (iii) receipt of any notification with respect to the suspension of
the qualification or exemption from qualification of any of the Shares for
sale in any jurisdiction or the initiation or threatening of any proceeding
for such purpose; (iv) the happening of any event that makes any statement
made in the Registration Statement or related prospectus or any document
incorporated or deemed to be incorporated therein by reference untrue in any
material respect or that requires the making of any changes in the
Registration Statement, related prospectus or documents so that, in the case
of the Registration Statement, it will not contain any untrue statement of a
material fact or omit to state any material fact required to be stated
therein or necessary to make the statements therein not misleading, and that
in the case of the related prospectus, it will not contain any untrue
statement of a material fact or omit to state any material fact required to
be stated therein or necessary to make the statements therein, in the light
of the circumstances under which they were made, not misleading; and (v) the
Company's reasonable determination that filing of a post-effective amendment
or withdrawal of the Registration Statement would be appropriate. The Company
shall not deliver to the Purchaser any Draw Down Notice during the
continuation of any of the

                                      13

<PAGE>

foregoing events. The Company shall promptly make available to the Purchaser
any such supplements or amendments to the related prospectus, at which time,
provided that the registration statement and any supplements and amendments
thereto are then effective, the Company may recommence the delivery of Draw
Down Notices.

                  Section 3.10. CONSOLIDATION; MERGER. The Company shall not,
at any time after the date hereof, effect any merger or consolidation of the
Company with or into, or a transfer of all or substantially all of the assets
of the Company to, another entity (a "Consolidation Event") unless the
resulting successor or acquiring entity (if not the Company) assumes by
written instrument or by operation of law the obligation to deliver to the
Purchaser such shares of stock and/or securities as the Purchaser is entitled
to receive pursuant to this Agreement.

                  Section 3.11. LIMITATION ON FUTURE FINANCING. Other than as
required by the Millenium Agreement, the Company shall not enter into any
other stand-by equity based credit facility until the earlier of (a) the date
on which an aggregate of $30,000,000 shall have been drawn pursuant hereto by
the Company and (b) termination of this Agreement in accordance with Article
6 hereof.

                  Section 3.12. USE OF PROCEEDS. The proceeds from the sale
of the Shares will be used by the Company and its subsidiaries for general
corporate purposes.

                  Section 3.13. STATEMENT OF COMPANY'S COUNSEL. Within ten
(10) Trading Days after the Effective Date, the Company shall furnish to the
Purchaser the following written statement by the Company's outside counsel,
addressed to the Purchaser and dated such Settlement Date:
         "In the course of the preparation by the Company of the Registration
         Statement and the Prospectus, we have participated in discussions with
         the Purchaser's representatives and those of the Company and its
         independent accountants, in which the business and affairs of the
         Company and the contents of the Registration Statement and the
         Prospectus were discussed. On the basis of information that we have
         gained in the course of our representation of the Company in connection
         with its preparation of the Registration Statement and the Prospectus
         and our participation in the discussions referred to above, we believe
         that the Registration Statement, as of its effective date, and the
         Prospectus, as of its effective date, complied as to form in all
         material respects with the requirements of the Act and the published
         rules and regulations of the SEC thereunder, and we do not know of any
         legal or governmental proceeding to which the Company or any of its
         subsidiaries is a party or to which any of its property is subject
         required to be described in the Prospectus which is not so described.
         Further, based on such information and participation, nothing that has
         come to our attention has caused us to believe that the Registration
         Statement at the time the Registration Statement became effective
         contained any untrue statement of a material fact or omitted to state
         any material fact required to be stated therein or necessary to make
         the statements therein not misleading, or that the Prospectus as of
         their date and as of the date of this opinion contained or contains any
         untrue statement of material fact or omitted or omit to state any
         material fact necessary to

                                      14

<PAGE>

         make the statements therein, in light of the circumstances under
         which they were made, not misleading. We express no opinion,
         however, with respect to the financial statements, including the
         notes and the schedules thereto, or any other financial, accounting
         or statistical information set forth or referred to in the
         Registration Statement or the Prospectus. The limitations inherent
         in the independent verification of factual matters and the character
         of the determinations involved in our review are such that we do not
         assume any responsibility for the accuracy, completeness or fairness
         of the statements made or the information contained in the
         Registration Statement or Prospectuses except for those made under
         the captions "Description of Capital Stock" and "Shares Eligible for
         Future Sale," which accurately and fairly summarize in all material
         respects the provisions of the laws and documents referred to
         therein."

                  The Purchaser covenants with the Company as follows:

                  Section 3.14. COMPLIANCE WITH LAW. The Purchaser agrees
that its trading activities with respect to shares of the Company's Common
Stock will be in compliance with all applicable state and federal securities
laws, rules and regulations and rules and regulations of the Principal Market
on which the Company's Common Stock is listed. Without limiting the
generality of the foregoing, the Purchaser agrees that it will, whenever
required by federal securities laws, deliver the prospectus included in the
Registration Statement to any purchaser of Shares from the Purchaser.

                  Section 3.15. NO SHORT SALES. The Purchaser and its
affiliates shall not engage in short sales of the Company's Common Stock (as
defined in applicable SEC rules and the Principal Market rules) during the
term of this Agreement.

                                    ARTICLE 4

                  CONDITIONS TO INITIAL CLOSING AND DRAW DOWNS

                  Section 4.1. CONDITIONS PRECEDENT TO THE OBLIGATION OF THE
COMPANY TO SELL THE SHARES. The obligation hereunder of the Company to
proceed to close this Agreement and to issue and sell the Shares to the
Purchaser pursuant to a Draw Down Notice delivered hereunder is subject to
the satisfaction or waiver, at or before the Initial Closing, and as of each
Settlement Date, of each of the conditions set forth below. These conditions
are for the Company's sole benefit and may be waived by the Company at any
time in its sole discretion.

                           (a) ACCURACY OF THE PURCHASER'S REPRESENTATIONS AND
         WARRANTIES. The representations and warranties of the Purchaser shall
         be true and correct in all material respects as of the date when made
         and as of the Initial Closing and as of each Settlement Date as though
         made at that time, except for representations and warranties that speak
         as of a particular date.

                                      15

<PAGE>

                           (b) PERFORMANCE BY THE PURCHASER. The Purchaser shall
         have performed, satisfied and complied in all material respects with
         all material covenants, agreements and conditions required by this
         Agreement to be performed, satisfied or complied with by the Purchaser
         at or prior to the Initial Closing and as of each Settlement Date.

                           (c) NO INJUNCTION. No statute, rule, regulation,
         executive order, decree, ruling or injunction shall have been enacted,
         entered, promulgated or endorsed by any court or governmental authority
         of competent jurisdiction which prohibits the consummation of any of
         the transactions contemplated by this Agreement.

                  Section 4.2. CONDITIONS PRECEDENT TO THE OBLIGATION OF THE
PURCHASER TO CLOSE. The obligation hereunder of the Purchaser to perform its
obligations under this Agreement and to purchase the Shares is subject to the
satisfaction or waiver, at or before the Initial Closing, of each of the
conditions set forth below. These conditions are for the Purchaser's sole
benefit and may be waived by the Purchaser at any time in its sole discretion.

                           (a) ACCURACY OF THE COMPANY'S REPRESENTATIONS AND
         WARRANTIES. Each of the representations and warranties of the Company
         shall be true and correct in all material respects as of the date when
         made and as of the Initial Closing as though made at that time (except
         for representations and warranties that speak as of a particular date).

                           (b) PERFORMANCE BY THE COMPANY. The Company shall
         have performed, satisfied and complied in all respects with all
         covenants, agreements and conditions required by this Agreement to be
         performed, satisfied or complied with by the Company at or prior to the
         Initial Closing.

                           (c) NO INJUNCTION. No statute, rule, regulation,
         executive order, decree, ruling or injunction shall have been enacted,
         entered, promulgated or endorsed by any court or governmental authority
         of competent jurisdiction which prohibits the consummation of any of
         the transactions contemplated by this Agreement.

                           (d) NO PROCEEDINGS OR LITIGATION. No action, suit or
         proceeding before any arbitrator or any governmental authority shall
         have been commenced, and no investigation by any governmental authority
         shall have been threatened, against the Purchaser or the Company or any
         subsidiary, or any of the officers, directors or affiliates of the
         Company or any subsidiary seeking to restrain, prevent or change the
         transactions contemplated by this Agreement, or seeking damages in
         connection with such transactions.

                           (e) OPINION OF COUNSEL, ETC.  At the Initial
         Closing, the Purchaser shall have received an opinion of counsel to
         the Company, dated as of the Initial Closing Date, in the form of
         EXHIBIT C hereto.

                           (f) WARRANT. On the Initial Closing Date, the Company
         shall issue to the Purchaser a warrant to purchase up to 250,000 shares
         of Common Stock. The

                                      16

<PAGE>

         Warrant shall have a term from its initial date of exercise of 3
         years. The exercise price of the Warrant shall be 115% of the
         average of the closing bid prices of the Common Stock (as reported
         by Bloomberg Financial L.P. at 4:02 p.m. ET on the Principal Market)
         during the 15 Trading Days immediately prior to the Initial Closing
         Date. The Common Stock underlying the Warrant will be registered in
         the Registration Statement referred to in Section 4.3 hereof. The
         Warrant shall be in the form of EXHIBIT E hereto.

                  Section 4.3. CONDITIONS PRECEDENT TO THE OBLIGATION OF THE
PURCHASER TO ACCEPT A DRAW DOWN AND PURCHASE THE DRAW DOWN SHARES. The
obligation hereunder of the Purchaser to accept a Draw Down request and to
acquire and pay for the Draw Down Shares is subject to the satisfaction at or
before each Settlement Date, of each of the conditions set forth below.

                           (a) SATISFACTION OF CONDITIONS TO INITIAL CLOSING.
         The Company shall have satisfied at the Initial Closing, or the
         Purchaser shall have waived at the Initial Closing, the conditions set
         forth in Section 4.2 hereof

                           (b) EFFECTIVE REGISTRATION STATEMENT. The
         Registration Statement registering the Shares shall have been declared
         effective by the SEC and shall remain effective on each Settlement
         Date.

                           (c) NO SUSPENSION. Trading in the Company's Common
         Stock shall not have been suspended by the SEC or the Principal Market
         (except for any suspension of trading of limited duration agreed to by
         the Company, which suspension shall be terminated prior to the delivery
         of each Draw Down Notice), and, at any time prior to such Draw Down
         Notice, trading in securities generally as reported on the Principal
         Market shall not have been suspended or limited, or minimum prices
         shall not have been established on securities whose trades are reported
         on the Principal Market unless the general suspension or limitation
         shall have been terminated prior to the delivery of such Draw Down
         Notice.

                           (d) MATERIAL ADVERSE EFFECT. No Material Adverse
         Effect and no Consolidation Event where the successor entity has not
         agreed to perform the Company's obligations hereunder shall have
         occurred since the later of the Initial Closing or the Settlement of
         the immediately preceding Draw Down, such occurrences to be determined
         in accordance with Section 8.9 herein.

                           (e) OPINION OF COUNSEL. The Purchaser shall have
         received (i) a "down-to-date" letter from the Company's counsel,
         confirming that there is no change from the counsel's previously
         delivered opinion, or else specifying with particularity the reason for
         any change and an opinion as to the additional items specified in
         EXHIBIT C hereto, (ii) a Form 424(b)(3) supplemental prospectus, if
         required by applicable law and (iii) any other items set forth in the
         Escrow Agreement (not including the escrow fee if the Escrow Agent is
         not used for such Draw Down).

                                      17

<PAGE>

                                    ARTICLE 5

                                 DRAW DOWN TERMS

         Section 5.1. DRAW DOWN TERMS. Subject to the satisfaction of the
conditions set forth in this Agreement, the parties agree as follows:

                           (a) The Company may, in its sole discretion, issue
         and exercise draw downs against the Commitment Amount (each a "Draw
         Down") during the Commitment Period, which Draw Downs the Purchaser
         shall be obligated to accept, subject to the terms and conditions
         herein.

                           (b) Only one Draw Down shall be allowed in each Draw
         Down Pricing Period. There shall be a minimum of one (1) Trading Day
         between Draw Down Pricing Periods. The number of shares of Common Stock
         purchased by the Purchaser with respect to each Draw Down shall be
         determined as set forth in Section 5.1(e) herein and settled on:

                                    (i) as to the 1st through the 10th Trading
                  Day during the Draw Down Pricing Period, on or before the 12th
                  Trading Day after such Draw Down Pricing Period commences; and

                                    (ii) as to the 11th through the 20th Trading
                  Day during the Draw Down Pricing Period, on or before the 22nd
                  Trading Day after such Draw Down Pricing Period commences
                  (such settlement periods and such settlement dates in
                  subsection (i) and this subsection (ii) each referred to as a
                  "Settlement Period" and a "Settlement Date", respectively).

                           (c) In connection with each Draw Down Pricing Period,
         the Company may set the Threshold Price in the Draw Down Notice.

                           (d) The minimum Investment Amount for any Draw Down
         shall be $250,000 and the maximum Investment Amount as to each Draw
         Down shall be 6% of the EQY weighted average price field (as reported
         on Bloomberg Financial L.P. using the BLPH function) for the 60
         calendar days immediately prior to the applicable Commencement Date
         (defined below) multiplied by the total trading volume in respect of
         the Common Stock for such period. Notwithstanding anything herein to
         the contrary, in the event the minimum Investment Amount is greater
         than the maximum Investment Amount, as to such Draw Down only, the
         minimum Investment Amount shall equal the maximum Investment Amount,
         but in no event shall the minimum Investment Amount be less than
         $100,000, such that if the maximum Investment Amount is less than
         $100,000, then the Company shall be precluded from exercising a Draw
         Down at such time.

                           (e) The number of Shares of Common Stock to be issued
         on each Settlement Date shall be a number of shares equal to the sum of
         the quotients (for each trading day within the Settlement Period) of
         (x) 1/20th of the Investment Amount, and

                                      18

<PAGE>

         (y) the Purchase Price on each Trading Day within the Settlement
         Period, subject to the following adjustments:

                                    (i) if the VWAP on a given Trading Day is
                  less than the Threshold Price, then that portion of the
                  Investment Amount to be paid on the immediately pending
                  Settlement Date shall be reduced by 1/20th of the Investment
                  Amount and such Trading Day shall be withdrawn from the
                  Settlement Period;

                                    (ii) if during any Trading Day during the
                  Settlement Period trading of the Common Stock on the Principal
                  Market is suspended for more than three (3) hours, in the
                  aggregate, or if any Trading Day during the Settlement Period
                  is shortened because of a public holiday, then that portion of
                  the Investment Amount to be paid on the immediately pending
                  Settlement Date shall be reduced by 1/20th of the Investment
                  Amount and such Trading Day shall be withdrawn from the
                  Settlement Period; and

                                    (iii) if during any Trading Day during the
                  Settlement Period sales of Draw Down Shares pursuant to the
                  Registration Statement are suspended by the Company in
                  accordance with Sections 3(j) or 5(e) of the Registration
                  Rights Agreement for more than three (3) hours, in the
                  aggregate, during the Settlement Period, then that portion of
                  the Investment Amount to be paid on the immediately pending
                  Settlement Date shall be reduced by 1/20th of the Investment
                  Amount and such Trading Day shall be withdrawn from the
                  Settlement Period.

                           (f) The Company must inform the Purchaser by
         delivering a draw down notice, in the form of EXHIBIT D hereto (the
         "Draw Down Notice"), via facsimile transmission in accordance with
         Section 8.4 as to the amount of the Draw Down (the "Investment Amount")
         the Company wishes to exercise, before the first day of the Draw Down
         Pricing Period (the "Commencement Date"). If the Commencement Date is
         to be the date of the Draw Down Notice, the Draw Down Notice must be
         delivered to and receipt confirmed by the Purchaser at least one (1)
         hour before trading commences on such date. At no time shall the
         Purchaser be required to purchase more than the maximum Investment
         Amount for a given Draw Down Pricing Period; in other words, if the
         Company chooses not to exercise the maximum Investment Amount in a
         given Draw Down Pricing Period the Purchaser is not obligated to and
         shall not purchase more than the scheduled maximum Investment Amount in
         a subsequent Draw Down Pricing Period.

                           (g) On each Settlement Date, the Shares purchased by
         the Purchaser during the immediately preceding Settlement Period shall
         be delivered to The Depository Trust Company ("DTC") on the Purchaser's
         behalf. Upon the Company electronically delivering whole shares of
         Common Stock to the Purchaser or its designees via DTC through its
         Deposit Withdrawal Agent Commission ("DWAC") system by 1:00 p.m. New
         York time, the Purchaser shall wire transfer immediately available
         funds to the Company's designated account on such day, less any fees as
         set forth in the Escrow Agreement, which fees shall be wired as
         directed in the Escrow Agreement. Upon the

                                      19

<PAGE>

         Company electronically delivering whole shares of Common
         Stock to the Purchaser or its designees DTC account via DWAC after
         1:00 p.m. New York time, the Purchaser shall wire transfer next day
         available funds to the Company's designated account on such day,
         less any fees as set forth in the Escrow Agreement, which fees shall
         be wired as directed in the Escrow Agreement. In the event that
         either party elects to use the Escrow Agent, the Shares shall be
         credited by the Company to the DTC account designated by the
         Purchaser via DWAC upon receipt by the Escrow Agent of payment for
         the Draw Down Shares into the Escrow Agent's master escrow account,
         as further set forth in the Escrow Agreement, and the Escrow Agent
         shall be directed to pay the purchase price to the Company, net of
         $1,000 per Settlement as escrow expenses to the Escrow Agent and any
         additional fees as set forth in the Escrow Agreement. The Company
         understands that a delay in the delivery of the Draw Down Shares
         into the Purchaser's DTC account beyond 5 Trading Days after the
         dates set forth herein or in the Escrow Agreement, as the case may
         be, could result in economic loss to the Purchaser. Notwithstanding
         anything herein to the contrary, as compensation to the Purchaser
         for such loss, the Company agrees to pay late payments to the
         Purchaser for late delivery after 5 Trading Days from such dates in
         accordance with the following schedule (where "No. Trading Days
         Late" is defined as the number of Trading Days beyond three 5
         Trading Days from the dates set forth herein or in the Escrow
         Agreement, as the case may be, on which such Draw Down Shares are to
         be delivered into the Purchaser's DTC account via the DWAC system):

<TABLE>
<CAPTION>
------------------------------------------------------------ ---------------------------------------------------------
                  No. Trading Days Late                                        Late Payment for Each
                                                                               $5,000 of Draw Down Shares
                                                                               Being Purchased
                  <S>                                                          <C>
------------------------------------------------------------ ---------------------------------------------------------
                  1                                                            $100
------------------------------------------------------------ ---------------------------------------------------------
                  2                                                            $200
------------------------------------------------------------ ---------------------------------------------------------
                  3                                                            $300
------------------------------------------------------------ ---------------------------------------------------------
                  4                                                            $400
------------------------------------------------------------ ---------------------------------------------------------
                  5                                                            $500
------------------------------------------------------------ ---------------------------------------------------------
                  6                                                            $600
------------------------------------------------------------ ---------------------------------------------------------
                  7                                                            $700
------------------------------------------------------------ ---------------------------------------------------------
                  8                                                            $800
------------------------------------------------------------ ---------------------------------------------------------
                  9                                                            $900
------------------------------------------------------------ ---------------------------------------------------------
                  10                                                           $1,000
------------------------------------------------------------ ---------------------------------------------------------
                  More than 10                                                 $1,00 +$200 for each Trading
                                                                               Day Late beyond 10 Trading
                                                                               Days.
------------------------------------------------------------ ---------------------------------------------------------
</TABLE>

                           The Company shall pay any payments incurred under
         this Section 5.1(g) in immediately available funds upon demand. Nothing
         herein shall limit the Purchaser's right to pursue injunctive relief
         and/or actual damages (in lieu of the liquidated damages set forth
         above) for the Company's failure to issue and deliver the Draw Down
         Shares to the Company, including, without limitation, the Purchaser's
         actual losses occasioned by any "buy-in" of Common Stock necessitated
         by such late delivery.

                                      20

<PAGE>

                                    ARTICLE 6

                                   TERMINATION

                  Section 6.1. TERM. The term of this Agreement shall begin
on the date hereof and shall end 30 months from the Effective Date or as
otherwise set forth in Section 6.2.

                  Section 6.2. OTHER TERMINATION.

                           (a) This Agreement shall terminate upon one (1)
         Trading Day's notice if (i) an event resulting in a Material Adverse
         Effect has occurred and has not been cured for a period of 30 days
         after written notice thereof, (ii) the Common Stock is de-listed from
         the Principal Market for a period exceeding 3 consecutive days unless
         such de-listing is in connection with the Company's subsequent listing
         of the Common Stock on the Nasdaq National Market, Nasdaq SmallCap
         Market, the American Stock Exchange or the New York Stock Exchange, or
         (iii) the Company files for protection from creditors under any
         applicable law.

                           (b) The Company may terminate this Agreement upon one
         (1) Trading Day's notice if the Purchaser shall fail to fund more than
         one properly noticed Draw Down within 4 Trading Days of the end of the
         applicable Settlement Period.

                  Section 6.3. EFFECT OF TERMINATION. In the event of
termination of this Agreement pursuant to Section 6.2 herein, written notice
thereof shall forthwith be given to the other party and the transactions
contemplated by this Agreement shall be terminated without further action by
either party. If this Agreement is terminated as provided in Section 6.1 or
6.2 herein, this Agreement shall become void and of no further force and
effect, except for Sections 8.1, 8.2 and 8.9, and Article 7 herein. Nothing
in this Section 6.3 shall be deemed to release the Company or the Purchaser
from any liability for any breach under this Agreement, or to impair the
rights of the Company or the Purchaser to compel specific performance by the
other party of its obligations under this Agreement.

                                    ARTICLE 7

                                 INDEMNIFICATION

                  Section 7.1. General Indemnity.

                           (a) The Company agrees to indemnify and hold harmless
         the Purchaser (and its directors, officers, affiliates, agents,
         successors and assigns) from and against any and all losses,
         liabilities, deficiencies, costs, damages and expenses (including,
         without limitation, reasonable attorneys' fees, charges and
         disbursements) incurred by the Purchaser as a result of any material
         inaccuracy in or breach of the representations, warranties or covenants
         made by the Company herein.

                                      21

<PAGE>

                           (b) The Purchaser agrees to indemnify and hold
         harmless the Company and its directors, officers, affiliates, agents,
         successors and assigns from and against any and all losses,
         liabilities, deficiencies, costs, damages and expenses (including,
         without limitation, reasonable attorneys' fees, charges and
         disbursements) incurred by the Company as result of any material
         inaccuracy in or breach of the representations, warranties or covenants
         made by the Purchaser herein.

                  Section 7.2. INDEMNIFICATION PROCEDURE. Any party entitled
to indemnification under this Article 7 (an "Indemnified Party") will give
written notice to the indemnifying party of any matters giving rise to a
claim for indemnification; provided, that the failure of any party entitled
to indemnification hereunder to give notice as provided herein shall not
relieve the indemnifying party of its obligations under this Article 7 except
to the extent that the indemnifying party is actually prejudiced by such
failure to give notice. In case any action, proceeding or claim is brought
against an Indemnified Party in respect of which indemnification is sought
hereunder, the indemnifying party shall be entitled to participate in and,
unless in the reasonable judgment of counsel to the Indemnified Party a
conflict of interest between it and the indemnifying party may exist with
respect of such action, proceeding or claim, to assume the defense thereof
with counsel reasonably satisfactory to the Indemnified Party. In the event
that the indemnifying party advises an Indemnified Party that it will contest
such a claim for indemnification hereunder, or fails, within thirty (30) days
of receipt of any indemnification notice to notify, in writing, such person
of its election to defend, settle or compromise, at its sole cost and
expense, any action, proceeding or claim (or discontinues its defense at any
time after it commences such defense), then the Indemnified Party may, at its
option, defend, settle or otherwise compromise or pay such action or claim.
In any event, unless and until the indemnifying party elects in writing to
assume and does so assume the defense of any such claim, proceeding or
action, the Indemnified Party's costs (including reasonable attorneys' fees,
charges and disbursements) and expenses arising out of the defense,
settlement or compromise of any such action, claim or proceeding shall be
losses subject to indemnification hereunder. The Indemnified Party shall
cooperate fully with the indemnifying party in connection with any settlement
negotiations or defense of any such action or claim by the indemnifying party
and shall furnish to the indemnifying party all information reasonably
available to the Indemnified Party, which relates to such action or claim.
The indemnifying party shall keep the Indemnified Party fully apprised at all
times as to the status of the defense or any settlement negotiations with
respect thereto. If the indemnifying party elects to defend any such action
or claim, then the Indemnified Party shall be entitled to participate in such
defense with counsel of its choice at its sole cost and expense. The
indemnifying party shall not be liable for any settlement of any action,
claim or proceeding effected without its prior written consent.
Notwithstanding anything in this Article 7 to the contrary, the indemnifying
party shall not, without the Indemnified Party's prior written consent (which
consent shall not be unreasonably withheld), settle or compromise any claim
or consent to entry of any judgment in respect thereof which imposes any
future obligation on the Indemnified Party or which does not include, as an
unconditional term thereof, the giving by the claimant or the plaintiff to
the Indemnified Party of a release from all liability in respect of such
claim. The indemnity agreements contained herein shall be in addition to (a)
any cause of action or similar rights of the Indemnified Party against the
indemnifying party or

                                      22

<PAGE>

others, and (b) any liabilities to which the indemnifying party may be
subject in each case pursuant to applicable law, rules or regulations.

                                    ARTICLE 8

                                  MISCELLANEOUS

                  Section 8.1. FEES AND EXPENSES. Each of the parties to this
Agreement shall pay its own fees and expenses related to the transactions
contemplated by this Agreement; except that, the Company shall pay, at the
Initial Closing, a non-accountable expense allowance of $25,000 for the
Purchaser's legal, administrative and due diligence costs and expenses and
any other additional fees as set forth in the Escrow Agreement. The Company
shall pay all stamp or other similar taxes and duties levied in connection
with issuance of the Shares pursuant hereto.

                  Section 8.2. SPECIFIC ENFORCEMENT. The Company and the
Purchaser acknowledge and agree that irreparable damage would occur in the
event that any of the provisions of this Agreement were not performed in
accordance with their specific terms or were otherwise breached. It is
accordingly agreed that the parties shall be entitled to an injunction or
injunctions to prevent or cure breaches of the provisions of this Agreement
and to enforce specifically the terms and provisions hereof or thereof, this
being in addition to any other remedy to which any of them may be entitled by
law or equity.

                  Section 8.3. ENTIRE AGREEMENT; AMENDMENT. The Transaction
Documents contain the entire understanding of the parties with respect to the
matters covered in the Transaction Documents. No provision of this Agreement
may be waived or amended other than by a written instrument signed by the
party against whom enforcement of any such amendment or waiver is sought and
no condition to closing any Draw Down in favor of the Purchaser may be waived
by the Purchaser.

                  Section 8.4. NOTICES. Any notice, demand, request, waiver
or other communication required or permitted to be given hereunder shall be
in writing and shall be effective (a) upon hand delivery or facsimile at the
address or number designated below (if delivered on a business day during
normal business hours where such notice is to be received), or the first
business day following such delivery (if delivered other than on a business
day during normal business hours where such notice is to be received) or (b)
on the second business day following the date of mailing by express courier
service, fully prepaid, addressed to such address, or upon actual receipt of
such mailing, whichever shall first occur. The addresses for such
communications shall be:

If to the Company:             3155 Porter Drive

                                      23

<PAGE>

                               Palo Alto, CA 94304
                               Attn:  Martin McGlynn, Chief Executive Officer
                                      Iris Brest, General Counsel
                               Tel: (650) 475-3100
                               Fax: (650) 475-3101

with copies to:                Ropes & Gray
(which shall not constitute    One International Place
notice)                        Boston, MA 02110
                               Attn: Geoffrey B. Davis
                               Tel: (617) 951-7000
                               Fax: (617) 951-7050

If to Purchaser:               c/o Beacon Capital Management
                               Harbour House, 2nd Floor
                               Waterfront Drive, Road Town
                               Tortola, British Virgin Islands
                               Attn: David Sims
                               Fax: (284) 494-4090

with copies to:                Epstein Becker & Green P.C.
(which shall not constitute    250 Park Avenue
notice)                        New York, NY  10177-1211
                               Tel: (212) 351-3771
                               Fax: (212) 661-0989
                               Attn: Robert F. Charron

                  Any party hereto may from time to time change its address
for notices by giving written notice of such changed address to the other
party hereto in accordance herewith.

                  Section 8.5. WAIVERS. No waiver by either party of any
default with respect to any provision, condition or requirement of this
Agreement shall be deemed to be a continuing waiver in the future or a waiver
of any other provisions, condition or requirement hereof, nor shall any delay
or omission of any party to exercise any right hereunder in any manner impair
the exercise of any such right accruing to it thereafter.

                  Section 8.6. HEADINGS. The article, section and subsection
headings in this Agreement are for convenience only and shall not constitute
a part of this Agreement for any other purpose and shall not be deemed to
limit or affect any of the provisions hereof.

                  Section 8.7. SUCCESSORS AND ASSIGNS. This Agreement and the
rights and obligations thereunder may not be assigned by either party without
the written consent of the other party. This Agreement shall be binding upon
and inure to the benefit of the parties and their successors and assigns. The
parties hereto may not amend this Agreement or any rights or obligations
hereunder without the prior written consent of the Company and the Purchaser.

                                      24

<PAGE>

                  Section 8.8. NO THIRD PARTY BENEFICIARIES.This Agreement is
intended for the benefit of the parties hereto and their respective permitted
successors and assigns and is not for the benefit of, nor may any provision
hereof be enforced by, any other person, including without limitation, any
assignee of some or all of the rights to purchase the Warrant Shares pursuant
to the Warrant.

                  Section 8.9. GOVERNING LAW/ARBITRATION. This Agreement
shall be governed by and construed in accordance with the internal laws of
the State of New York, without giving effect to the choice of law provisions.
The Company and the Purchaser agree to submit themselves to the IN PERSONAM
jurisdiction of the state and federal courts situated within the Southern
District of the State of New York with regard to any dispute or controversy
arising out of or relating to this Agreement. Any dispute or controversy
under this Agreement or any Exhibit attached hereto shall be submitted to
arbitration under the American Arbitration Association (the "AAA") in New
York City, New York, and shall be finally and conclusively determined by the
decision of a board of arbitration consisting of three (3) members
(hereinafter referred to as the "Board of Arbitration") selected as according
to the rules governing the AAA. The Board of Arbitration shall meet on
consecutive business days in New York City, New York, and shall reach and
render a decision in writing (concurred in by a majority of the members of
the Board of Arbitration) with respect to the amount, if any, which the
losing party is required to pay to the other party in respect of a claim
filed. In connection with rendering its decisions, the Board of Arbitration
shall adopt and follow the laws of the State of New York. To the extent
practical, decisions of the Board of Arbitration shall be rendered no more
than thirty (30) calendar days following commencement of proceedings with
respect thereto. The Board of Arbitration shall cause its written decision to
be delivered to all parties involved in the dispute. The Board of Arbitration
shall be authorized and is directed to enter a default judgment against any
party refusing to participate in the arbitration proceeding within thirty
days of any deadline for such participation. Any decision made by the Board
of Arbitration (either prior to or after the expiration of such thirty (30)
calendar day period) shall be final, binding and conclusive on the parties to
the dispute, and entitled to be enforced to the fullest extent permitted by
law and entered in any court of competent jurisdiction. The prevailing party
shall be awarded its costs, including reasonable attorneys' fees, from the
non-prevailing party as part of the arbitration award. Any party shall have
the right to seek injunctive relief, including without limitation as set
forth in Section 8.2, from any court of competent jurisdiction in any case
where such relief is available. The prevailing party in such injunctive
action shall be awarded its costs, including reasonable attorneys' fees, from
the non-prevailing party.

                  Section 8.10. COUNTERPARTS. This Agreement may be executed
in any number of counterparts, all of which taken together shall constitute
one and the same instrument and shall become effective when counterparts have
been signed by each party and delivered to the other parties hereto, it being
understood that all parties need not sign the same counterpart. Execution may
be made by delivery by facsimile.

                  Section 8.11. PUBLICITY. Except as required by law or
regulations or the rules of the Principal Market, neither the Company nor the
Purchaser shall issue any press release or otherwise make any public
statement or announcement with respect to this Agreement or the transactions
contemplated hereby or the existence of this Agreement, without the prior
written

                                      25

<PAGE>

consent of the other party. In connection with the Initial Closing, if the
Company deems it necessary or desirable, the Company may issue a press
release or file an appropriate report with the SEC regarding the transactions
contemplated hereby; PROVIDED, HOWEVER, that prior to issuing any such press
release, making any such public statement or announcement, the Company
obtains the prior consent of the Purchaser, which consent shall not be
unreasonably withheld or delayed.

                  Section 8.12. SEVERABILITY. The provisions of this
Agreement are severable and, in the event that The Board of Arbitration or
any court or officials of any regulatory agency of competent jurisdiction
shall determine that any one or more of the provisions or part of the
provisions contained in this Agreement shall, for any reason, be held to be
invalid, illegal or unenforceable in any respect, such invalidity, illegality
or unenforceability shall not affect any other provision or part of a
provision of this Agreement and this Agreement shall be reformed and
construed as if such invalid or illegal or unenforceable provision, or part
of such provision, had never been contained herein, so that such provisions
would be valid, legal and enforceable to the maximum extent possible, so long
as such construction does not materially adversely affect the economic rights
of either party hereto.

                  Section 8.13. FURTHER ASSURANCES. From and after the date
of this Agreement, upon the request of the Purchaser or the Company, each of
the Company and the Purchaser shall execute and deliver such instruments,
documents and other writings as may be reasonably necessary or desirable to
confirm and carry out and to effectuate fully the intent and purposes of this
Agreement.

                  Section 8.14. EFFECTIVENESS OF AGREEMENT. This Agreement
shall become effective only upon satisfaction of the conditions precedent to
the Initial Closing set forth in Article I of the Escrow Agreement.

                  Section 8.15. CONFIDENTIALITY. The Purchaser understands
that the CPI has been developed or obtained by the Company by the investment
of significant time, effort and expense and that such CPI provides the
Company with significant competitive advantages in its businesses. The
Purchaser therefore agrees (i) to maintain all CPI in confidence and take all
necessary precautions to protect said CPI, including without limitation, all
precautions the Purchaser normally employs with respect to its own
confidential materials but in no event less than a reasonable degree of care;
(ii) not to divulge CPI or any information derived therefrom outside of
Purchaser; and (iii) not to utilize said CPI for any purpose other than as
necessary for purposes of performance under this Agreement. The foregoing
sentence shall not apply with respect to information the Purchaser can
establish (i) is in the public domain at the time of disclosure or which
thereafter enters the public domain, through no improper action or inaction
by the Purchaser; or (ii) was known to or independently developed by or in
the possession of Purchaser prior to receipt of such CPI from the Company, as
evidenced by written records; or (iii) was lawfully disclosed to the
Purchaser by a third party without restriction; or (iv) is required to be
disclosed by a government agency or court order or pursuant to applicable
laws and regulations PROVIDED that within five days of notification of such a
requirement and prior to complying with such requirement the Purchaser shall
notify the Company of such requirement pursuant to clause (iv) and shall
limit the disclosure to that portion of the CPI which is legally

                                      26

<PAGE>

required in the written opinion of counsel and shall use best efforts to
ensure such CPI is treated confidentially.

                                    ARTICLE 9

                                   DEFINITIONS

                  Section 9.1. Certain Definitions.

                           (a) "COMMENCEMENT DATE" shall have the meaning
         assigned to such term in Section 5.1(f) hereof.

                           (b) "COMMITMENT AMOUNT" shall have the meaning
         assigned to such term in Section 1.1 hereof.

                           (c) "COMMITMENT PERIOD" shall mean the period
         commencing on the Effective Date and expiring on the earliest to occur
         of (i) the date on which the Purchaser shall have exercised an
         aggregate amount of Draw Downs equal to the Commitment Amount, (ii) the
         date this Agreement is terminated in accordance with the terms hereof,
         or (iii) the date occurring 30 months after the Effective Date.

                           (d) "COMMON STOCK" shall mean the Company's common
         stock, $0.01 par value per share.

                           (e) "CPI" shall mean all oral and written information
         concerning the Company which is non-public, confidential or proprietary
         in nature and shall include, but not be limited to, existing,
         future-developed or acquired products, processes, techniques, methods,
         agents, computer programs, trade secrets, and other information
         regarding the business of the Company, know-how, ideas (including
         patentable ideas), inventions, unpublished patent applications,
         improvements, copyrightable materials, schematics, product development
         plans, forecasts, strategies, customers, suppliers, regulatory
         strategies and other technical, business, financial, marketing and
         merchandising information of the Company.

                           (f) "DISCLOSURE SCHEDULE" shall mean the
         schedules prepared by the Company and attached hereto.

                           (g) "DRAW DOWN" shall have the meaning assigned to
         such term in Section 5.1(a) hereof.

                           (h) "DRAW DOWN NOTICE" shall have the meaning
         assigned to such term in Section 5.1(f) hereof.

                           (i) "DRAW DOWN PRICING PERIOD" shall mean a period of
         twenty (20) consecutive Trading Days beginning on the date specified in
         the Draw Down Notice (as defined in Section 5.1(f) herein); PROVIDED,
         HOWEVER, the Draw Down Pricing Period shall not begin before the day on
         which receipt of such notice is confirmed by the Purchaser.

                                      27

<PAGE>

                           (j) "DTC" shall have the meaning assigned to such
         term in Section 5.1(g).

                           (k) "DWAC" shall have the meaning assigned to such
         term in Section 5.1(g).

                           (l) "EFFECTIVE DATE" shall mean the date the
         Registration Statement of the Company covering the Shares being
         subscribed for hereby is declared effective by the SEC.

                           (m) "ENGAGEMENT LETTER" shall mean the letter
         agreement dated as of April 24, 2001, between the Company and Pacific
         Crest Securities, Inc.

                           (n) "EXCHANGE ACT" shall mean the Securities Exchange
         Act of 1934, as amended, and the rules and regulations promulgated
         thereunder.

                           (o) "GAAP" shall mean the United States Generally
         Accepted Accounting Principles as those conventions, rules and
         procedures are determined by the Financial Accounting Standards Board
         and its predecessor agencies.

                           (p) "INITIAL CLOSING" shall have the meaning assigned
         to such term in Section 1.2 hereof.

                           (q) "INITIAL CLOSING DATE" shall have the meaning
         assigned to such term in Section 1.2 hereof.

                           (r) "INVESTMENT AMOUNT" shall have the meaning
         assigned to such term in Section 5.1(f) hereof.

                           (s) "MATERIAL ADVERSE EFFECT" shall mean any adverse
         effect on the business, operations, properties or financial condition
         of the Company that is material and adverse to the Company and its
         subsidiaries and affiliates, taken as a whole and/or any condition,
         circumstance, or situation that would prohibit or otherwise materially
         interfere with the ability of the Company to perform any of its
         material obligations under this Agreement or the Registration Rights
         Agreement.

                           (t) "MATERIAL AGREEMENT" shall mean any written or
         oral contract, instrument, agreement, commitment, obligation, plan or
         arrangement, a copy of which is required to be filed with the SEC as an
         exhibit to any of the SEC Documents.

                           (u) "MILLENNIUM AGREEMENT" shall mean the
         Subscription Agreement dated as of July 31, 2000, between the Company
         and Millennium Partners, L.P. and the other agreements entered into in
         connection therewith.

                           (v) "PRINCIPAL MARKET" shall mean initially the
         Nasdaq National market and shall include the American Stock Exchange,
         the Nasdaq Small-Cap Market and the

                                      28

<PAGE>

         New York Stock Exchange if the Company becomes listed and trades on
         such market or exchange after the date hereof.

                           (w) "PURCHASE PRICE" shall mean, with respect to
         Shares purchased during each applicable Settlement Period, 94% (the
         "Purchase Price Percentage") of the VWAP on the date in question;
         EXCEPT THAT, the Purchase Price Percentage shall increase by 0.5% for
         each $50,000,000 increase in the Company's market cap (calculated by
         multiplying the number of shares of Common Stock issued and outstanding
         by the VWAP of the Common Stock on any date in question (the "Market
         Cap")) over $50,000,000 during the applicable Market Cap Period (as
         defined below); PROVIDED, that in no event shall the Purchase Price
         Percentage be more than 96%; PROVIDED, FURTHER, that such increases in
         the Purchase Price Percentage shall only occur if the increase in the
         Market Cap is maintained for at least twenty (20) consecutive Trading
         Days immediately prior to the date the applicable Draw Down Pricing
         Period commences (the "Market Cap Period"). By way of example, if the
         Market Cap as to a Market Cap Period is $99,999,999, the Purchase Price
         Percentage is 94% as to the applicable Draw Down. If the Market Cap as
         to a Market Cap Period is $101,000,000, the Purchase Price Percentage
         is 94.5% as to the applicable Draw Down. If the Market Cap as to a
         subsequent Market Cap Period is less than $100,000,000, the Purchase
         Price Percentage shall be 94% as to such Draw Down.

                           (x) "REGISTRATION STATEMENT" shall mean the
         registration statement under the Securities Act, to be filed with the
         Securities and Exchange Commission for the registration of the Shares
         pursuant to the Registration Rights Agreement attached hereto as
         EXHIBIT A (the "Registration Rights Agreement).

                           (y) "SEC" shall mean the Securities and Exchange
         Commission.

                           (z) "SEC DOCUMENTS" shall mean the Company's latest
         Form 10-K or Form 10-KSB as of the time in question, all Forms 10-Q or
         10-QSB and 8-K filed thereafter until the time in question, the Proxy
         Statement for its latest fiscal year as of the time in question, and
         any exhibits to the aforementioned documents, until such time as the
         Company no longer has an obligation to maintain the effectiveness of a
         Registration Statement as set forth in the Registration Rights
         Agreement.

                           (aa)"SECURITIES ACT" shall mean the Securities Act of
         1933, as amended, and the rules and regulations promulgated thereunder.

                           (bb)"SETTLEMENT" shall mean the delivery of the Draw
         Down Shares into the Purchaser's DTC account via DTC's DWAC System in
         exchange for payment therefor.

                           (cc)"SETTLEMENT DATE" shall have the meaning assigned
         to such term in Section 5.1(b).

                                      29

<PAGE>

                           (dd)"SETTLEMENT PERIOD" shall have the meaning
         assigned to such term in Section 5.1(b).

                           (ee)"SHARES" shall mean, collectively, the shares of
         Common Stock of the Company being subscribed for hereunder (the "Draw
         Down Shares") and the shares of Common Stock issuable upon exercise of
         the Warrant (the "Warrant Shares").

                           (ff) "THRESHOLD PRICE" shall mean the price per Share
         designated by the Company as the lowest VWAP during any Draw Down
         Pricing Period at which the Company shall sell its Common Stock in
         accordance with this Agreement.

                           (gg)"TRADING DAY" shall mean any day on which the
         Principal Market is open for business.

                           (hh)"TRANSACTION DOCUMENTS" shall mean this
         Agreement, the Registration Rights Agreement and the Escrow Agreement.

                           (ii) "VWAP" shall mean the daily volume weighted
         average price of the Company's Common Stock on the Principal Market as
         reported by Bloomberg Financial L.P. (based on a trading day from 9:30
         a.m. Eastern Time to 4:02 p.m. Eastern Time) using the VAP function on
         the date in question.

                           (jj) "WARRANT" shall mean the warrant issued to the
         Purchaser pursuant to Section 4.2(f) hereof.

                            [SIGNATURE PAGE FOLLOWS]

                                      30

<PAGE>

               [SIGNATURE PAGE TO EQUITY LINE PURCHASE AGREEMENT]

                  IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be duly executed by their respective authorized officer as of
this 10th day of May, 2001.

                                      STEMCELLS INC.,

                                      By:  /s/ Martin McGlynn
                                          --------------------------------------
                                            Martin McGlynn, President & CEO

                                      SATIVUM INVESTMENTS LIMITED

                                      By:  /s/ David Sims
                                          --------------------------------------
                                            David Sims, Director

                                      31<PAGE>

                                                                   Exhibit 10.51

                                ESCROW AGREEMENT

                  THIS ESCROW AGREEMENT (this "Agreement") is made as of May
10, 2001, by and among StemCells, Inc., a corporation incorporated under the
laws of Delaware (the "Company"), Sativum Investments Limited ("Purchaser"),
and Epstein Becker & Green, P.C., having an address at 250 Park Avenue, New
York, NY 10177 (the "Escrow Agent"). Capitalized terms used but not defined
herein shall have the meanings set forth in the Common Stock Purchase
Agreement referred to in the first recital.

                  WHEREAS, the Purchaser will from time to time as requested
by the Company, purchase shares of the Company's Common Stock from the
Company as set forth in that certain Common Stock Purchase Agreement (the
"Purchase Agreement") dated the date hereof between the Purchaser and the
Company, which shares shall be issued pursuant to the terms and conditions
contained herein and in the Purchase Agreement; and

                  WHEREAS, the Company and the Purchaser have requested that
the Escrow Agent hold in escrow and then distribute the initial documents and
certain funds which are conditions precedent to the effectiveness of the
Purchase Agreement, and have further requested that upon each exercise of a
Draw Down, the Escrow Agent hold the relevant documents and the applicable
purchase price pending receipt by Purchaser of the securities issuable upon
such Draw Down;

                  NOW, THEREFORE, in consideration of the covenants and
mutual promises contained herein and other good and valuable consideration,
the receipt and legal sufficiency of which are hereby acknowledged and
intending to be legally bound hereby, the parties agree as follows:

                                    ARTICLE I

                  TERMS OF THE ESCROW FOR THE INITIAL CLOSING

                  1.1. The parties hereby agree to establish an escrow
account with the Escrow Agent whereby the Escrow Agent shall hold the funds
and documents, which are referenced in Section 4.2 of the Purchase Agreement.

                  1.2. At the Initial Closing, the Company shall deliver to
the Escrow Agent:

                       (i)      the original executed Registration Rights
                                Agreement in the form of EXHIBIT A to the
                                Purchase Agreement;

                       (ii)     the original executed opinion of Ropes &
                                Gray in the form of EXHIBIT C to the
                                Purchase Agreement;

                       (iii)    the sum of $25,000 as a non-accountable
                                expense allowance for the Purchaser's legal,
                                administrative and due diligence costs and
                                expenses;

<PAGE>

                       (iv)     the sum of $25,000 as a non-accountable
                                expense allowance for Pacific Crest
                                Securities, Inc.'s ("Pacific Crest") legal
                                and administrative costs and expenses;

                       (v)      the original executed Company counterpart of
                                this Escrow Agreement;

                       (vi)     the original executed Company counterpart of
                                the Purchase Agreement;

                       (vii)    a warrant issued to Pacific Crest
                                Securities, Inc. to purchase up to 75,000
                                shares of Common Stock otherwise identical
                                to that of the Warrant ("PC Warrant");

                       (viii)   a warrant issued to Granite Financial Group,
                                Inc. to purchase up to 25,000 shares of
                                Common Stock otherwise identical to that of
                                the Warrant (the "Granite Warrant"); and

                       (ix)     the original executed Warrant.

                  1.3. Upon receipt of the foregoing, and receipt of executed
counterparts from Purchaser of the Purchase Agreement, the Registration
Rights Agreement and this Escrow Agreement, the Escrow Agent shall calculate
and enter the exercise price, issuance date and termination date on the face
of the Warrant, PC Warrant and the Granite Warrant and immediately transfer
the sum of $25,000 as directed by the Purchaser and $25,000 as directed by
Pacific Crest, and shall then arrange to have the Purchase Agreement, this
Escrow Agreement, the Registration Rights Agreement, the Warrant, the PC
Warrant, the Granite Warrant and the opinion of counsel delivered to the
appropriate parties.

                  1.4 WIRE TRANSFERS to the Escrow Agent (NOT address for
notice or delivery of documents) shall be made as follows:

                                Epstein Becker & Green, P.C.
                                Master Escrow Account
                                Chase Manhattan Bank
                                1411 Broadway - Fifth Floor
                                New York, New York 10018
                                ABA No. 021000021
                                Account No. 035 1 346036
                                Attention: L. Borneo

                                      2

<PAGE>

                                   ARTICLE II

                     TERMS OF THE ESCROW FOR EACH DRAW DOWN

                  2.1. Each time the Company shall send a Draw Down Notice to
the Purchaser as provided in the Purchase Agreement, it shall send a copy, by
facsimile, to the Escrow Agent. Either party shall notify the Escrow Agent
and the other party contemporaneously with the delivery of each Draw Down
Notice whether it intends to use the Escrow Agent to effect the Settlements
associated with such Draw Down.

                  2.2. Each time the Purchaser shall purchase Shares pursuant
to a Draw Down for which either party has elected to use the Escrow Agent,
the Purchaser shall send the applicable Purchase Price of the Draw Down
Shares to the Escrow Agent. Upon receipt of such funds, the Escrow Agent
shall advise the Company that it has received the funds for such Draw Down
Shares. The Company shall promptly, but no later than one (1) Trading Day
after receipt of such funding notice from the Escrow Agent:

                       (i)      cause its transfer agent to issue the Draw
                                Down Shares to the Purchaser via DTC's DWAC
                                system to the account specified by the
                                Purchaser from time to time;

                       (ii)     deliver the original executed attorney's
                                opinion in the form of EXHIBIT C to the
                                Purchase Agreement to the Purchaser; and

                       (iii)    deliver a Form 424(b)(3) supplemental
                                prospectus to the Purchaser.

                  2.3. Upon receipt of confirmation from the Purchaser that
such Draw Down Shares have been so deposited and the opinion and the
supplemental prospectus have been so delivered, the Escrow Agent shall, as
soon as practicable but not later than one (1) Trading Day of receipt of the
foregoing, wire 97% of the applicable Investment Amount per the written
instructions of the Company, net of one thousand dollars ($1,000) as escrow
expenses to the Escrow Agent, 2% of the applicable Investment Amount to
Pacific Crest and the remaining 1% of the applicable Investment Amount to
Granite Financial Group, Inc.

                  2.4. The Escrow Agent shall remit the Pacific Crest and
Granite Financial Group, Inc.'s fee in accordance with wire instructions that
Pacific Crest and Granite Financial Group, Inc., respectively, will send to
the Escrow Agent.

                  2.5. In the event that such Draw Down Shares are not in the
Purchaser's DTC account and the opinion and supplemental prospectus are not
delivered to the Purchaser within three (3) Trading Days of the date of the
Escrow Agent's notice, then Purchaser shall have the right to demand, by
notice, the return of the Purchase Price, and the applicable Draw Down Notice
shall be deemed cancelled.

                                      3

<PAGE>

                                   ARTICLE III

                                  MISCELLANEOUS

                  3.1. No waiver of any breach of any covenant or provision
herein contained shall be deemed a waiver of any preceding or succeeding
breach thereof, or of any other covenant or provision herein contained. No
extension of time for performance of any obligation or act shall be deemed an
extension of the time for performance of any other obligation or act.

                  3.2. All notices or other communications required or
permitted hereunder shall be in writing, and shall be sent by fax, overnight
courier, registered or certified mail, postage prepaid, return receipt
requested, and shall be deemed received as set forth in the Purchase
Agreement.

                  3.3. This Escrow Agreement shall be binding upon and shall
inure to the benefit of the permitted successors and permitted assigns of the
parties hereto.

                  3.4. This Escrow Agreement is the final expression of, and
contains the entire agreement between, the parties with respect to the
subject matter hereof and supersedes all prior understandings with respect
thereto. This Escrow Agreement may not be modified, changed, supplemented or
terminated, nor may any obligations hereunder be waived, except by written
instrument signed by the parties or by their respective agents duly
authorized in writing or as otherwise expressly permitted herein.

                  3.5. Whenever required by the context of this Escrow
Agreement, the singular shall include the plural and masculine shall include
the feminine. This Escrow Agreement shall not be construed as if it had been
prepared by one of the parties, but rather as if all parties had prepared the
same. Unless otherwise indicated, all references to Articles are to this
Escrow Agreement.

                  3.6. The parties hereto expressly agree that this Escrow
Agreement shall be governed by, interpreted under and construed and enforced
in accordance with the laws of the State of New York. Except as expressly set
forth herein, any action to enforce, arising out of, or relating in any way
to, any provisions of this Escrow Agreement shall be brought as is more fully
set forth in the Purchase Agreement.

                  3.7. The Escrow Agent's duties hereunder may be altered,
amended, modified or revoked only by a writing signed by the Company,
Purchaser and the Escrow Agent.

                  3.8. The Escrow Agent shall be obligated only for the
performance of such duties as are specifically set forth herein and may rely
and shall be protected in relying or refraining from acting on any instrument
reasonably believed by the Escrow Agent to be genuine and to have been signed
or presented by the proper party or parties. The Escrow Agent shall not be
personally liable for any act the Escrow Agent may do or omit to do hereunder
as the Escrow Agent while acting in good faith, excepting only its own gross
negligence or willful misconduct.

                                      4

<PAGE>

                  3.9. The Escrow Agent is hereby expressly authorized to
disregard any and all warnings given by any of the parties hereto or by any
other person or corporation, excepting only orders or process of courts of
law and is hereby expressly authorized to comply with and obey orders,
judgments or decrees of any court. In case the Escrow Agent obeys or complies
with any such order, judgment or decree, the Escrow Agent shall not be liable
to any of the parties hereto or to any other person, firm or corporation by
reason of such decree being subsequently reversed, modified, annulled, set
aside, vacated or found to have been entered without jurisdiction.

                  3.10. The Escrow Agent shall not be liable in any respect
on account of the identity, authorization or rights of the parties executing
or delivering or purporting to execute or deliver the Purchase Agreement or
any documents or papers deposited or called for thereunder or hereunder,
except as a result of the Escrow Agent's gross negligence or willful
misconduct.

                  3.11. The Escrow Agent shall be entitled to employ such
legal counsel and other experts as the Escrow Agent may deem necessary
properly to advise the Escrow Agent in connection with the Escrow Agent's
duties hereunder, may rely upon the advice of such counsel, and may pay such
counsel reasonable compensation therefor, which cost shall be shared equally
by the Company and the Purchaser. THE ESCROW AGENT HAS ACTED AS LEGAL COUNSEL
FOR THE PURCHASER, AND MAY CONTINUE TO ACT AS LEGAL COUNSEL FOR THE
PURCHASER, FROM TIME TO TIME, NOTWITHSTANDING ITS DUTIES AS THE ESCROW AGENT
HEREUNDER. THE COMPANY CONSENTS TO THE ESCROW AGENT IN SUCH CAPACITY AS LEGAL
COUNSEL FOR THE PURCHASER AND WAIVES ANY CLAIM THAT SUCH REPRESENTATION
REPRESENTS A CONFLICT OF INTEREST ON THE PART OF THE ESCROW AGENT. THE
COMPANY UNDERSTANDS THAT THE PURCHASER AND THE ESCROW AGENT ARE RELYING
EXPLICITLY ON THE FOREGOING PROVISION IN ENTERING INTO THIS ESCROW AGREEMENT.
If a conflict of interest shall arise, the parties agree to arrange for a
successor escrow agent.

                  3.12. The Escrow Agent's responsibilities as escrow agent
hereunder shall terminate if the Escrow Agent shall resign by written notice
to the Company and the Purchaser. In the event of any such resignation, the
Purchaser and the Company shall appoint a successor Escrow Agent. The
Purchaser and the Company may remove the Escrow Agent and appoint a successor
at any time by mutual agreement.

                  3.13. If the Escrow Agent reasonably requires other or
further instruments in connection with this Escrow Agreement or obligations
in respect hereto, the necessary parties hereto shall join in furnishing such
instruments.

                  3.14. It is understood and agreed that should any dispute
arise with respect to the delivery and/or ownership or right of possession of
the documents or the escrow funds held by the Escrow Agent hereunder, the
Escrow Agent is authorized and directed in the Escrow Agent's sole discretion
(i) to retain in the Escrow Agent's possession without liability to anyone
all or any part of said documents or the escrow funds until such disputes
shall have been settled either by mutual written agreement of the parties
concerned by a final order, decree or judgment of a board of arbitration or a
court of competent jurisdiction after the time for appeal has expired and no
appeal has been perfected, but the Escrow Agent shall be under no duty
whatsoever to institute or defend any such proceedings or (ii) to deliver the
escrow funds and any other property and documents held by the Escrow Agent
hereunder to a state or Federal court having competent

                                      5

<PAGE>

subject matter jurisdiction and located in the State and City of New York in
accordance with the applicable procedure therefor.

                  3.15. The Company and the Purchaser agree jointly and
severally to indemnify and hold harmless the Escrow Agent and its partners,
employees, agents and representatives from any and all claims, liabilities,
costs or expenses (including reasonable attorneys' fees) in any way arising
from or relating to the duties or performance of the Escrow Agent hereunder
or the transactions contemplated hereby or by the Purchase Agreement other
than any such claim, liability, cost or expense to the extent the same shall
have been determined by final, unappealable judgment of a court of competent
jurisdiction to have resulted from the gross negligence or willful misconduct
of the Escrow Agent.

                                      6

<PAGE>

                 [SIGNATURE PAGE TO EQUITY LINE ESROW AGREEMENT]

IN WITNESS WHEREOF, the parties hereto have executed this Escrow Agreement as
of this 10th day of May, 2001.

                                    STEMCELLS INC.

                                    By:  /s/ Martin McGlynn
                                        ----------------------------------------
                                         Martin McGlynn, President & CEO

                                    SATIVUM INVESTMENTS LIMITED

                                    By:  /s/ David Sims
                                        ----------------------------------------
                                          David Sims, Director

                                    ESCROW AGENT:

                                    EPSTEIN BECKER & GREEN, P.C.

                                    By:  /s/ Robert F. Charron
                                        ----------------------------------------
                                        Robert F. Charron, Authorized Signatory

                                      7

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