<PAGE>

                                                                    EXHIBIT 10.3


                              INVENTA CORPORATION


                        ______________________________

            SERIES C CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT

                        ______________________________



                                 May 11, 1998
<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>

                                                                            Page
                                                                            ----
<S>                                                                         <C>
1.   Purchase and Sale of Series C Preferred Stock..........................  1

     1.1  Sale and Issuance of Series C Preferred Stock.....................  1
     1.2  Closing Date; Delivery............................................  1

2.   Representations and Warranties of the Company..........................  1
     2.1   Organization, Good Standing and Qualification....................  1
     2.2   Capitalization...................................................  2
     2.3   Subsidiaries.....................................................  2
     2.4   Authorization....................................................  2
     2.5   Valid Issuance of Securities.....................................  2
     2.6   Governmental Consents............................................  3
     2.7   Litigation.......................................................  3
     2.8   Patent and Trademarks............................................  3
     2.9   Compliance with Other Instruments................................  4
     2.10  Disclosure.......................................................  4
     2.11  Registration Rights..............................................  4
     2.12  Title to Property and Assets.....................................  4
     2.13  Financial Statements.............................................  5
     2.14  Changes..........................................................  5
     2.15  Minute Books.....................................................  6
     2.16  Labor Agreements and Actions.....................................  6
     2.17  Employee Plans...................................................  7
     2.18  Employees........................................................  7
     2.19  Tax Returns and Payments.........................................  7
     2.20  Agreements; Action...............................................  7
     2.21  Obligations to Related Parties...................................  9
     2.22  Real Property Holding Corporation................................  9
     2.23  Insurance........................................................  9
     2.24  Investment Company Act...........................................  9
     2.25  Qualified Small Business.........................................  9

3.   Representations and Warranties of the Investors........................  9

     3.1   Authorization....................................................  9
     3.2   Purchase Entirely for Own Account................................  9
     3.3   Disclosure of Information........................................ 10
     3.4   Economic Risk.................................................... 10
     3.5   Restricted Securities............................................ 10
     3.6   Further Limitations on Disposition............................... 10
     3.7   Legends.......................................................... 11

4.   California Commissioner of Corporations................................ 11

     4.1   Corporate Securities Law......................................... 11
</TABLE>

                                      -i-
<PAGE>

<TABLE>
<S>                                                                         <C>
5.   Conditions of Investor's Obligations at Closing........................ 12

     5.1   Representations and Warranties................................... 12
     5.2   Performance...................................................... 12
     5.3   Articles of Incorporation........................................ 12
     5.4   Compliance Certificate........................................... 12
     5.5   Restated Shareholders Agreement.................................. 12
     5.6   Restated Registration Rights Agreement........................... 12
     5.7   Employment Agreement............................................. 12
     5.8   Opinion of Company's Counsel..................................... 12
     5.9   Legal Expenses................................................... 12
     5.10  Management Rights Agreement...................................... 13

6.   Conditions of the Company's Obligations at Closing..................... 13

     6.1   Representations and Warranties................................... 13
     6.2   Payment of Purchase Price........................................ 13
     6.3   Legal Matters.................................................... 13

7.   Covenants of the Company............................................... 13

     7.1   Delivery of Financial Statements................................. 13
     7.2   Inspection Rights................................................ 14
     7.3   Reservation of Common Stock...................................... 14
     7.4   Proprietary Information Agreement................................ 14
     7.5   Termination of Information Covenant.............................. 14
     7.6   Key Man Life Insurance........................................... 14
     7.7   Chief Executive Officer Recruitment.............................. 14

8.   Miscellaneous.......................................................... 14

     8.1  Transfer; Successors and Assigns.................................. 14
     8.2  Governing Law..................................................... 14
     8.3  Counterparts...................................................... 15
     8.4  Titles and Subtitles.............................................. 15
     8.5  Notices........................................................... 15
     8.6  Finder's Fee...................................................... 15
     8.7  Expenses.......................................................... 15
     8.8  Amendments and Waivers............................................ 15
     8.9  Severability...................................................... 15
     8.10  Entire Agreement................................................. 15
     8.11  Exculpation Among Investors...................................... 16
</TABLE>

                                     -ii-
<PAGE>

                                    EXHIBITS
                                    --------

EXHIBIT A   Schedule of Investors

EXHIBIT B   Amended and Restated Articles of Incorporation

EXHIBIT C   Schedule of Exceptions to Representations and Warranties

EXHIBIT D   Form of Proprietary Information Agreement

EXHIBIT E   Restated Shareholders Agreement

EXHIBIT F   Restated Registration Rights Agreement

EXHIBIT G   Opinion of Wilson Sonsini Goodrich & Rosati

EXHIBIT H   Management Rights Agreement


                                     -iii-
<PAGE>

            SERIES C CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT
            -------------------------------------------------------


     THIS SERIES C CONVERTIBLE PREFERRED STOCK PURCHASE AGREEMENT ("Agreement")
is made as of the 11th day of May 1998 by and between Inventa Corporation, a
California corporation (the "Company"), and the persons and entities listed on
the Schedule of Investors attached hereto as Exhibit A (the "Investors").
                                             ---------

     THE PARTIES HEREBY AGREE AS FOLLOWS:

     1.   Purchase and Sale of Series C Preferred Stock
          ---------------------------------------------

          1.1  Sale and Issuance of Series C Preferred Stock
               ---------------------------------------------

               (a)  The Company shall adopt and file with the Secretary of State
of California on or before the Closing (as defined below) the Amended and
Restated Articles of Incorporation in the form attached hereto as Exhibit B.
                                                                  ---------

               (b)  Subject to the terms and conditions of this Agreement, the
Investors agree to purchase at the Closing and the Company agrees to sell and
issue to the Investors at the Closing that number of shares of the Company's
Series C Preferred Stock (the "Shares") for the aggregate purchase price set
forth opposite each Investor's name on Exhibit A attached hereto, at a purchase
                                       ---------
price equal to $1.25 per share of Series C Preferred Stock.

          1.2  Closing Date; Delivery. The purchase and sale of the Shares shall
               ----------------------
take place at the offices of Wilson Sonsini Goodrich & Rosati, 650 Page Mill
Road, Palo Alto, California, at 9:00 a.m., on May 11, 1998, or at such other
time and place as the Company and the Investors mutually agree upon, orally or
in writing (which time and place are designated as the "Closing"). At the
Closing, the Company shall deliver to each Investor a certificate representing
the Shares which such Investor is purchasing against delivery to the Company by
such Investor of a check made payable to the Company or wire transfer of the
aggregate purchase price therefor.

     2.   Representations and Warranties of the Company. The Company hereby
          ---------------------------------------------
represents and warrants to the Investors that, except as set forth on a Schedule
of Exceptions attached hereto as Exhibit C, specifically identifying the
                                 ---------
relevant subparagraph hereof, which exceptions shall be deemed to be
representations and warranties as if made hereunder:

          2.1. Organization, Good Standing and Qualification . The Company is a
               ---------------------------------------------
corporation duly organized, validly existing and in good standing under the
laws of the State of California and has all requisite corporate power and
authority to carry on its business as now conducted and as proposed to be
conducted. The Company is duly qualified to transact business and is in good
standing in each jurisdiction in which the failure so to qualify would have a
material adverse effect on its business or properties.
<PAGE>

          2.2  Capitalization.  The authorized capital of the Company will
               --------------
consist, immediately prior to the Closing, of (i) 8,119,511 shares of Preferred
Stock, 1,000,000 shares of which are designated Series A Preferred Stock and of
which 800,000 are issued and outstanding, 2,560,000 shares of which are
designated Series B Preferred Stock and of which 2,560,000 are issued and
outstanding, and 4,059,511 shares of which are designated Series C Preferred
Stock of which none are issued and outstanding, and (ii) 25,000,000 shares of
Common Stock, of which 4,642,344 shares are issued and outstanding. The Company
has reserved 1,350,000 shares of its Common Stock for issuance pursuant to its
1993 Stock Option Plan. Except as set forth in the Schedule of Exceptions
attached as Exhibit C hereto, there are no outstanding options, warrants, rights
(including conversion or preemptive rights) or agreements, orally or in writing,
for the purchase or acquisition from the Company of any shares of its capital
stock.

          2.3  Subsidiaries.  Except as set forth in the Schedule of Exceptions,
               ------------
the Company does not presently own or control, directly or indirectly, any
interest in any other corporation, association, or other business entity.

          2.4  Authorization.  All corporate action on the part of the Company,
               -------------
its officers, directors and shareholders necessary for the authorization,
execution and delivery of this Agreement, the performance of all obligations of
the Company hereunder and the authorization, issuance and delivery of the Shares
has been taken or will be taken prior to the Closing, and this Agreement
constitutes a valid and legally binding obligation of the Company, enforceable
in accordance with its terms. The Agreement, the Restated Shareholders Agreement
attached hereto as Exhibit E (the "Restated Shareholders Agreement") and the
                   ---------
Restated Registration Rights Agreement attached hereto as Exhibit F (the
                                                          ---------
"Restated Registration Rights Agreement"), when executed and delivered, will be
valid and binding obligations of the Company enforceable in accordance with
their terms, except (i) as limited by applicable bankruptcy, insolvency,
reorganization, moratorium or other laws of general application affecting
enforcement of creditors' rights; (ii) general principles of equity that
restrict the availability of equitable remedies; and (iii) to the extent that
the enforceability of the indemnification provisions in Section 10 of the
Restated Registration Rights Agreement may be limited by applicable laws. The
sale of the Shares and the subsequent conversion of the Shares into Common Stock
are not and will not be subject to any preemptive rights or rights of first
refusal that have not been properly waived or complied with.

          2.5  Valid Issuance of Securities.
               ----------------------------

               (a)  The Shares that are being issued to the Investors hereunder,
when issued, sold and delivered in accordance with the terms hereof for the
consideration expressed herein, will be duly and validly issued, fully paid and
nonassessable. The shares of Common Stock issuable upon conversion of the Shares
have been duly and validly reserved for issuance.

               (b)  The shares of Common Stock and Preferred Stock outstanding
prior to the Closing are all duly and validly authorized and issued, fully paid
and nonassessable and were issued in compliance with all applicable state and
federal laws concerning the issuance of securities.

                                      -2-
<PAGE>

          2.6  Governmental Consents.  No consent, approval, order or
               ---------------------
authorization of, or registration, qualification, designation, declaration or
filing with, any federal, state or local governmental authority on the part of
the Company is required in connection with the consummation of the transactions
contemplated by this Agreement, except for (a) the filing pursuant to Section
25102(f) of the California Corporate Securities Law of 1968, as amended, and the
rules thereunder, which filing will be effected in accordance with such section,
and (b) compliance with the Blue Sky Laws of the various states in which the
Investors may reside, which compliance will be effected in accordance with such
laws. The Company currently holds all licenses, permits, franchises,
registrations and qualifications which may be required to conduct its business,
and all such licenses, permits, franchises, registrations and qualifications are
valid and in full force and effect.

          2.7  Litigation.  Except as set forth in the Schedule of Exceptions,
               ----------
there is no action, suit, proceeding or investigation pending or currently
threatened against the Company that questions the validity of this Agreement or
the right of the Company to enter into it, or to consummate the transactions
contemplated hereby, or that might result, either individually or in the
aggregate, in any material adverse changes in the assets, condition, affairs or
prospects of the Company, financially or otherwise, or any change in the current
equity ownership of the Company, nor is the Company aware that there is any
basis for the foregoing. The foregoing includes, without limitation, actions
pending or threatened (or any basis therefor known to the Company) involving the
prior employment of any of the Company's employees, their use in connection with
the Company's business of any information or techniques allegedly proprietary to
any of their former employers, or their obligations under any agreements with
prior employers. The Company is not a party or subject to the provisions of any
order, writ, injunction, judgment or decree of any court or government agency or
instrumentality. There is no action, suit, proceeding or investigation by the
Company currently pending or which the Company intends to initiate.

          2.8  Patent and Trademarks.  To its knowledge, the Company owns or
               ---------------------
possesses sufficient legal rights to all patents, trademarks, service marks,
trade names, copyrights, trade secrets, information and other proprietary rights
and processes necessary for its business as now conducted and as proposed to be
conducted, without any known infringement of the rights of others. There are no
outstanding options, licenses or agreements of any kind relating to the
foregoing, nor is the Company bound by or a party to any options, licenses or
agreements of any kind with respect to the patents, trademarks, service marks,
trade names, copyrights, trade secrets, licenses, information and other
proprietary rights and processes of any other person or entity other than such
licenses or agreements arising from the purchase or sale of "off the shelf" or
standard products. The Company has not received any communications alleging that
the Company has violated or, by conducting its business as proposed, would
violate any of the patents, trademarks, service marks, trade names, copyrights
or trade secrets or other proprietary rights of any other person or entity. The
Company is not aware that any of its employees is obligated under any contract
(including licenses, covenants or commitments of any nature) or other agreement,
or subject to any judgment, decree or order of any court or administrative
agency, that would interfere with their duties to the Company or that would
conflict with the Company's business as proposed to be conducted. Neither the
execution nor

                                      -3-
<PAGE>

delivery of this Agreement, nor the carrying on of the Company's business by the
employees of the Company, nor the conduct of the Company's business as proposed,
will, to the Company's knowledge, conflict with or result in a breach of the
terms, conditions or provisions of, or constitute a default under, any contract,
covenant or instrument under which any employee is now obligated. The Company
does not believe it is or will be necessary to utilize any inventions, trade
secrets or proprietary information of any of its employees made prior to their
employment by the Company, except for inventions, trade secrets or proprietary
information that have been assigned to the Company.

          2.9  Compliance with Other Instruments.
               ---------------------------------

               (a)  The Company is not in violation or default of any provisions
of its Amended and Restated Articles of Incorporation or Bylaws or of any
instrument, judgment, order, writ, decree or contract to which it is a party or
by which it is bound or, to its knowledge, of any provision of federal or state
statute, rule or regulation applicable to the Company. The execution, delivery
and performance of this Agreement and the consummation of the transactions
contemplated hereby will not result in any such violation or be in conflict with
or constitute, with or without the passage of time and giving of notice, either
a default under any such provision, instrument, judgment, order, writ, decree,
contract, rule, or statute, or of the Company's Restated Articles of
Incorporation or Bylaws, or an event which results in the creation of any lien,
charge or encumbrance upon any assets of the Company.

               (b)  The Company has avoided every condition, and has not
performed any act, the occurrence of which would result in the Company's loss of
any right granted under any license, distribution or other agreement.

          2.10 Disclosure.  The Company has fully provided the Investors with
               ----------
all the information which the Investors have requested for deciding whether to
acquire the Shares and all information which the Company believes is reasonably
necessary to enable the Investors to make such decision. There is no information
known to the Company which materially adversely affects the business or
operations of the Company which has not been disclosed to the Investors. Neither
this Agreement nor any other statements or certificates made or delivered in
connection herewith contains any untrue statement of a material fact or omits to
state a material fact necessary to make the statements herein or therein not
misleading, except that, with respect to financial projections, the Company
represents only that such projections were prepared in good faith and that the
Company believes there is a reasonable basis for such projections.

          2.11 Registration Rights.  Except as set forth in the Restated
               -------------------
Registration Rights Agreement, the Company has not granted or agreed to grant
any registration rights, including piggyback rights, to any person or entity.

          2.12 Title to Property and Assets.  The Company owns its property and
               ----------------------------
assets free and clear of all mortgages, liens, loans and encumbrances, except
such encumbrances and liens

                                      -4-
<PAGE>

which arise in the ordinary course of business and do not materially impair the
Company's ownership or use of such property or assets. With respect to the
property and assets it leases, the Company is in compliance with such leases
and, to the best of its knowledge, holds a valid leasehold interest free of any
liens, claims or encumbrances. All facilities, machinery, equipment, fixtures,
vehicles and other properties owned, leased or used by the Company are in good
operating condition and repair (normal wear and tear accepted) and are
reasonably fit and usable for the purposes for which they are being used.

          2.13 Financial Statements.  The Company has delivered to the Investors
               --------------------
its unaudited financial statements (balance sheet and profit and loss statement
and statement of shareholders equity) at December 31, 1997 and for the fiscal
year then ended and a balance sheet and statement of operations at March 31,
1998 (collectively, the "Financial Statements").  The Financial Statements are
complete and correct in all material respects and have been prepared in
accordance with generally accepted accounting principles applied on a consistent
basis throughout the periods indicated and with each other.  The Financial
Statements accurately set out and describe the financial condition and operating
results of the Company as of the dates, and for the periods, indicated therein.
Except as set forth in the Financial Statements, the Company has no liabilities,
contingent or otherwise, of a nature required by generally accepted accounting
principles to be reflected in a balance sheet or disclosed in the notes thereto,
other than liabilities incurred in the ordinary course of business subsequent to
March 31, 1998

          2.14 Changes.  Since March 31, 1998, there has not been:
               -------

               (a)  any change in the assets, liabilities, financial condition
or operating results of the Company from that reflected in the Financial
Statements, except changes in the ordinary course of business which have not
been, in the aggregate, materially adverse.

               (b)  any damage, destruction or loss, whether or not covered by
insurance, materially and adversely affecting the assets, properties, financial
condition, operating results, prospects or business of the Company (as such
business is presently conducted and as it is proposed to be conducted);

               (c)  any waiver by the Company of a valuable right or of a
material debt owed to it;

               (d)  any satisfaction or discharge of any lien, claim or
encumbrance or payment of any obligation by the Company, except in the ordinary
course of business and which is not material to the assets, properties,
financial condition, operating results or business of the Company (as such
business is presently conducted and as it is proposed to be conducted);

               (e)  any change or amendment to a material contract or
arrangement by which the Company or any of its assets or properties is bound or
to which the Company or any of such assets or properties is subject;

                                      -5-
<PAGE>

               (f)  any resignation or termination of any key officers of the
Company; and the Company, to its knowledge, does not know of the impending
resignation or termination of employment of any such officer;

               (g)  to the knowledge of the Company any material change, except
in the ordinary course of business, in the contingent obligations of the Company
by way of guaranty, endorsement, indemnity, warranty or otherwise;

               (h)  any direct or indirect loans made by the Company to any
shareholder, employee, officer or director of the Company, other than advances
made in the ordinary course of business or loans to purchase Common Stock;

               (i)  any material change in any compensation arrangement or
agreement with any employee, officer, director or shareholder other than in the
ordinary course of business;

               (j)  any declaration or payment of any dividend or other
distribution of the assets of the Company;

               (k)  any labor organization activity;

               (l)  any debt, obligation or liability incurred, assumed or
guaranteed by the Company, except those for immaterial amounts and for current
liabilities incurred in the ordinary course of business;

               (m)  any sale, assignment or transfer of any patents, trademarks,
copyrights, trade secrets or other intangible assets; or

               (n)  to the Company's knowledge, any other event or condition of
any character which might materially and adversely affect the assets,
properties, financial condition, operating results or business of the Company
(as such business is presently conducted and as it is proposed to be conducted).

          2.15 Minute Books.  The Company has offered to provide to the
               ------------
Investors the minute books of the Company, which contain a complete summary of
all meetings of directors and shareholders since the time of incorporation and
reflect all transactions referred to in such minutes accurately in all material
respects.

          2.16 Labor Agreements and Actions  .  The Company is not bound by or
               ----------------------------
subject to (and none of its assets or properties is bound by or subject to) any
written or oral, express or implied, contract, commitment or arrangement with
any labor union, and no labor union has requested or, to the knowledge of the
Company, has sought to represent any of the employees, representatives or agents
of the Company.  There is no strike or other labor dispute involving the Company
pending, or to the knowledge of the Company threatened, which could have a
material adverse effect on the

                                      -6-
<PAGE>

assets, properties, financial condition, operating results, or business of the
Company (as such business is presently conducted and as it is proposed to be
conducted), nor is the Company aware of any labor organization activity
involving its employees.

          2.17   Employee Plans.  The Company has no "employee welfare benefit
                 --------------
plans" as defined in Section 3(3) of the Employee Retirement Income Security Act
of 1974 ("ERISA"). The Company (i) has not been required to contribute to, (ii)
has not terminated or withdrawn from, and (iii) is not aware of any withdrawal
liability assessed against the Company with respect to any defined benefit plan
as defined in Section 3(35) of ERISA or multiemployer plan as defined in Section
4001 of ERISA in which employees or former employees of the Company have
participated.

          2.18   Employees.  The Company has not knowingly violated any
                 ---------
employment-related laws, including, without limitation, laws relating to equal
employment opportunity, overtime pay and collective bargaining. The Company is
not aware that any officer or key employee, or that any group of key employees,
intends to terminate their employment with the Company, nor does the Company
have a present intention to terminate the employment of any of the foregoing.
Except as set forth in the Schedule of Exceptions, the employment of each
officer and employee of the Company is terminable at the will of the Company.
Each former and current United States employee and consultant of the Company
with access to confidential or proprietary information has executed a
Proprietary Information Agreement, the form of which is attached hereto as
Exhibit D. To the Company's knowledge, no employee of the Company, nor any
---------
consultant with whom the Company has contracted, is in violation of any term of
any employment contract, proprietary information agreement or any other
agreement relating to the right of any such individual to be employed by, or to
contract with, the Company because of the nature of the business to be conducted
by the Company; and to the Company's knowledge the continued employment by the
Company of its present employees, and the performance of the Company's contracts
with its independent contractors, will not result in any such violation. The
Company has not received any notice alleging that any such violation has
occurred. The Company's relations with its employees is good.

          2.19   Tax Returns and Payments.  The Company has timely filed all tax
                 ------------------------
returns (federal, state and local) required to be filed by it.  All taxes shown
to be due and payable on such returns, any assessments imposed, and to the
Company's knowledge all other taxes due and payable by the Company on or before
the Closing have been paid or will be paid prior to the time they become
delinquent. The Company has not been advised except as set forth in the Schedule
of Exceptions (i) that any of its returns, federal, state or other, have been or
are being audited as of the date hereof, or (ii) of any deficiency in assessment
or proposed judgment to its federal, state or other taxes. The Company has no
knowledge of any liability of any tax to be imposed upon its properties or
assets as of the date of this Agreement that is not adequately provided for.

          2.20   Agreements; Action.
                 ------------------

                 (a)   Except for agreements explicitly contemplated hereby
including proprietary agreements and agreements between the Company and its
employees with respect to the

                                      -7-
<PAGE>

sale of the Company's Common Stock, and agreements between the Company and the
Investors with respect to their investment, there are no agreements,
understandings or proposed transactions between the Company and any of its
officers, directors, affiliates or any affiliate thereof.

               (b)  There are no agreements, understandings, instruments,
contracts, proposed transactions, judgments, orders, writs or decrees to which
the Company is a party or to its knowledge by which it is bound which may
involve (i) obligations (contingent or otherwise) of, or payments to, the
Company in excess of $25,000 (other than obligations of, or payments to, the
Company arising from purchase or sale agreements entered into in the ordinary
course of business), or (ii) the license of any patent, copyright, trade secret
or other proprietary right to or from the Company (other than licenses arising
from the purchase or sale of "off the shelf" or other standard products), or
(iii) provisions restricting or affecting the development, manufacture or
distribution of the Company's products or services, or (iv) indemnification by
the Company with respect to infringements of proprietary rights (other than
indemnification obligations arising from purchase or sale agreements entered
into in the ordinary course of business).

               (c)  The Company has not (i) declared or paid any dividends, or
authorized or made any distribution upon or with respect to any class or series
of its capital stock, (ii) incurred any indebtedness for money borrowed or any
other liabilities except as set forth in the Schedule of Exceptions (other than
with respect to dividend obligations, distributions, indebtedness and other
obligations incurred in the ordinary course of business or as disclosed in the
Financial Statements) individually in excess of $25,000 or, in the case of
indebtedness and/or liabilities individually less than $25,000, in excess of
$50,000 in the aggregate, (iii) made any loans or advances to any person, other
than ordinary advances for travel expenses, or (iv) sold, exchanged or otherwise
disposed of any material amount of its assets or rights, other than the sale of
its inventory in the ordinary course of business.

               (d)  For the purposes of subsections (b) and (c) above, all
indebtedness, liabilities, agreements, understandings, instruments, contracts
and proposed transactions involving the same person or entity (including persons
or entities the Company has reason to believe are affiliated therewith) shall be
aggregated for the purpose of meeting the individual minimum dollar amounts of
such subsections.

               (e)  Except as set forth in the Schedule of Exceptions, the
Company has not engaged in the past three (3) months in any material discussion
(i) with any representative of any corporation or corporations regarding the
consolidation or merger of the Company with or into any such corporation or
corporations, (ii) with any corporation, partnership, association or other
business entity or any individual regarding the sale, conveyance or disposition
of all or substantially all of the assets of the Company, or a transaction or
series of related transactions in which more than fifty percent (50%) of the
voting power of the Company is disposed of, or (iii) regarding any other form of
acquisition, liquidation, dissolution or winding up of the Company.

                                      -8-
<PAGE>

          2.21 Obligations to Related Parties.  There are no obligations of the
               ------------------------------
Company to officers, directors, shareholders or employees of the Company other
than (a) for payment of salary for services rendered, (b) reimbursement for
reasonable expenses incurred on behalf of the Company and (c) for other standard
employee benefits made generally available to all employees (including stock
option agreements outstanding under any stock option plan approved by the Board
of Directors of the Company).  Except as set forth in the Schedule of Exceptions
none of the officers, directors or shareholders of the Company, or any members
of their immediate families, are indebted to the Company or have any direct or
indirect ownership interest in any firm or corporation with which the Company is
affiliated or with which the Company has a business relationship, or any firm or
corporation which competes with the Company, except that officers, directors
and/or shareholders of the Company may own stock in publicly traded companies
which may compete with the Company.  No officer, director or shareholder, or any
member of their immediate families, is, directly or indirectly, interested in
any material contract with the Company (other than such contracts as relate to
any such person's ownership of capital stock or other securities of the
Company).  Except as may be disclosed in the Financial Statements, the Company
is not a guarantor or indemnitor of any indebtedness of any other person, firm
or corporation.

          2.22 Real Property Holding Corporation.  The Company is not a real
               ---------------------------------
property holding corporation within the meaning of Internal Revenue Code Section
897(c)(2) and any regulations promulgated thereunder.

          2.23 Insurance.  The Company has or will obtain promptly following
               ---------
Closing fire and casualty insurance policies with coverage customary for
companies similarly situated to the Company.

          2.24 Investment Company Act.  The Company is not an "investment
               ----------------------
company," or a company "controlled" by an "investment company," within the
meaning of the Investment Company Act of 1940, as amended.

          2.25 Qualified Small Business.  The Company represents and warrants to
               ------------------------
the Investors that, to its knowledge, the Shares should qualify as "Qualified
Small Business Stock" as defined in Section 1202(c) of the Internal Revenue Code
of 1986, as amended (the "Code") as of the date hereof.

     3.   Representations and Warranties of the Investors.  Each Investor for
          -----------------------------------------------
itself hereby represents and warrants to the Company that:

          3.1  Authorization.  This Agreement constitutes its valid and legally
               -------------
binding obligation, enforceable in accordance with its terms.

          3.2  Purchase Entirely for Own Account.  This Agreement is made with
               ---------------------------------
the Investor in reliance upon the Investor's representation to the Company,
which by the Investor's execution of this Agreement the Investor hereby
confirms, that the Shares will be acquired for

                                      -9-
<PAGE>

investment for the Investor's own account, not as a nominee or agent, and not
with a view to the resale or distribution of any part thereof, and that the
Investor has no present intention of selling, granting any participation in, or
otherwise distributing the same. By executing this Agreement, the Investor
further represents that the Investor does not presently have any contract,
undertaking, agreement or arrangement with any person to sell, transfer or grant
participations to such person or to any third person, with respect to any of the
Shares. The Investor represents that it has full power and authority to enter
into this Agreement.

          3.3   Disclosure of Information. The Investor believes it has
                -------------------------
received information that it considers necessary or appropriate for deciding
whether to acquire the Shares. The Investor further represents that it has had
an opportunity to ask questions and receive answers from the Company regarding
the terms and conditions of the offering of the Shares. The foregoing, however,
does not limit or modify the representations and warranties of the Company in
Section 2 of this Agreement or the right of the Investor to rely thereon.

          3.4   Economic Risk. The Investor has the capacity to protect his own
                -------------
interests in connection with the purchase of the Shares, is capable of
evaluating the merits and risks of investment in the Company, can make an
informed investment decision by reason of (i) his preexisting personal or
business relationship with the Company or any of its officers, directors, or
control persons, or (ii) his business and financial knowledge and experience or
the business and financial knowledge and experience of my professional advisers,
if any, and is able to bear the substantial economic risks of an investment in
the Shares for an indefinite period of time.

          3.5   Restricted Securities. It understands that the shares of Common
                ---------------------
Stock sold hereunder are characterized as "restricted securities" under the
federal securities laws inasmuch as they are being acquired from the Company in
a transaction not involving a public offering and that under such laws and
applicable regulations such shares may be resold without registration under the
Securities Act of 1933, as amended (the "Act"), only in certain limited
circumstances. In this connection, the Investor represents that he is familiar
with SEC Rule 144, as presently in effect, and understands the resale
limitations imposed thereby and by the Act.

          3.6   Further Limitations on Disposition. Without in any way
                ----------------------------------
limiting the representations set forth above, the Investor further agrees not to
make any disposition of all or any portion of the Shares unless and until:

                (a)  There is then in effect a Registration Statement under the
Act covering such proposed disposition and such disposition is made in
accordance with such Registration Statement; or

                (b)  (i) The Investor shall have notified the Company of the
proposed disposition and shall have furnished the Company with a detailed
statement of the circumstances surrounding the proposed disposition, and (ii) if
reasonably requested by the Company, the Investor

                                      -10-
<PAGE>

shall have furnished the Company with an opinion of counsel, reasonably
satisfactory to the Company, that such disposition will not require registration
under the Act.

                (c)  Notwithstanding the provisions of paragraphs (a) and (b
above, no such registration statement or opinion of counsel shall be necessary
for a transfer by the Investor to a shareholder, partner or other affiliate of
the Investor, if the transferee or transferees agree in writing to be subject to
the terms hereof to the same extent as if they were the Investor hereunder.

          3.7   Legends. It is understood that the Shares, and the shares of
                -------
Common Stock issuable upon conversion thereof and any securities issued in
respect thereof or exchanged therefor may bear one or all of the following
legends:

                (a)  THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE BEEN
ACQUIRED FOR INVESTMENT AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933. SUCH SHARES MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF SUCH
REGISTRATION OR UNLESS THE COMPANY RECEIVES AN OPINION OF COUNSEL REASONABLY
ACCEPTABLE TO IT STATING THAT SUCH SALE OR TRANSFER IS EXEMPT FROM THE
REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SAID ACT. COPIES OF THE
AGREEMENT COVERING THE PURCHASE OF THESE SHARES AND RESTRICTING THEIR TRANSFER
MAY BE OBTAINED AT NO COST BY WRITTEN REQUEST MADE BY THE HOLDER OF RECORD OF
THIS CERTIFICATE TO THE SECRETARY OF THE CORPORATION AT THE PRINCIPAL EXECUTIVE
OFFICES OF THE CORPORATION.

                (b)  Any legend required by the laws of the State of
California, including any legend required by the California Department of
Corporations.

                (c)  Any legend required by the Blue Sky laws of any other state
to the extent such laws are applicable to the shares represented by the
certificate so legended:

     4.   California Commissioner of Corporations.
          ---------------------------------------

          4.1   Corporate Securities Law. THE SALE OF THE SECURITIES THAT IS THE
                -------------------------
SUBJECT OF THIS AGREEMENT HAS NOT BEEN QUALIFIED WITH THE COMMISSIONER OF
CORPORATIONS OF THE STATE OF CALIFORNIA, THE ISSUANCE OF SUCH SECURITIES OR THE
PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION FOR SUCH SECURITIES PRIOR TO
SUCH QUALIFICATION IS UNLAWFUL, UNLESS THE SALE OF SECURITIES IS EXEMPT FROM THE
QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE CALIFORNIA CORPORATIONS
CODE. THE RIGHTS OF ALL PARTIES TO THIS AGREEMENT ARE EXPRESSLY CONDITIONED UPON
SUCH QUALIFICATION BEING OBTAINED UNLESS THE SALE IS SO EXEMPT.

                                      -11-
<PAGE>

     5.   Conditions of Investor's Obligations at Closing. The obligations of
          -----------------------------------------------
the Investors under Section 1.1 of this Agreement are subject to the
fulfillment, on or before the Closing, of each of the following conditions:

          5.1   Representations and Warranties. The representations and
                ------------------------------
warranties of the Company contained in Section 2 shall be true and correct in
all material respects as of the Closing.

          5.2   Performance. The Company shall have performed and complied with
                -----------
all agreements, obligations and conditions contained in this Agreement that are
required to be performed or complied with by it on or before the Closing.

          5.3   Articles of Incorporation. The Company shall have filed with,
                -------------------------
and have had accepted for filing by, the California Secretary of State the
Amended and Restated Articles of Incorporation of the Company attached as
Exhibit B hereto.
---------

          5.4   Compliance Certificate. The President of the Company shall
                ----------------------
deliver to the Investors at the Closing a certificate certifying that the
conditions specified in Sections 5.1 and 5.2 have been fulfilled.

          5.5   Restated Shareholders Agreement. Each key employee of the
                -------------------------------
Company who holds at least 100,000 shares of the capital stock of the Company
(on an as-converted basis and as adjusted for any stock split, stock dividends,
combinations, recapitalization and the like with respect to such shares) shall
have entered into a Restated Shareholders Agreement with the Company, in
substantially the form attached hereto as Exhibit E.
                                          ---------

          5.6   Restated Registration Rights Agreement. The Company shall
                --------------------------------------
deliver to the Investors at the Closing copies of the Restated Registration
Rights Agreement executed by the necessary majority of the signatories thereto.

          5.7   Employment Agreement. The Company shall at or prior to the
                --------------------
Closing enter into an employment agreement with Ashok Santhanam mutually
acceptable to the Company, Mr. Santhanam and the Investors.

          5.8   Opinion of Company's Counsel. The Purchasers shall have received
                ----------------------------
from Wilson Sonsini Goodrich & Rosati, counsel to the Company, an opinion
addressed to them, dated the Closing Date, in substantially the form of Exhibit
                                                                        -------
G.
-

          5.9   Legal Expenses. The Company shall pay the legal expenses of the
                --------------
Investors in connection with the Series C Preferred Stock financing in an
aggregate amount not to exceed $15,000.

                                      -12-
<PAGE>

          5.10  Management Rights Agreement. The Company shall deliver to the
                ---------------------------
Technology Crossover Ventures entities executed copies of the Management Rights
Agreement attached hereto as Exhibit H.
                             ---------

     6.   Conditions of the Company's Obligations at Closing. The obligations
          --------------------------------------------------
of the Company to the Investors under this Agreement are subject to the
fulfillment, on or before the Closing, of each of the following conditions by
the Investors:

          6.1   Representations and Warranties. The representations and
                ------------------------------
warranties of the Investors contained in Section 3 shall be true and correct in
all material respects as of the Closing.

          6.2   Payment of Purchase Price. The Investors shall have delivered
                -------------------------
to the Company the purchase price specified in Section 1.1 hereof.

          6.3   Legal Matters. All material matters of a legal nature which
                -------------
pertain to this Agreement, and the transactions contemplated hereby, shall have
been reasonably approved by counsel to the Company.

     7.   Covenants of the Company.
          ------------------------

          7.1   Delivery of Financial Statements. The Company shall deliver the
                --------------------------------
following financial information to each Investor who continues to hold at least
50,000 Shares (or the Common Stock into which the Shares have been converted)
(as adjusted for any stock split, stock dividends, combinations,
recapitalizations and the like with respect to such Shares)(for purposes of
satisfying the 50,000 share threshold herein, shares owned by partners,
subsidiaries, parents, shareholders or affiliates will be aggregated; provided,
however, that the Company shall only be required to deliver financial
information to one representative of each group of affiliated persons or
entities), and as long as such Investor or a principal, partner or manager of
such Investor, is not employed by or associated with a competitor of the
Company:

                (a)  as soon as practicable after the end of each fiscal year of
the Company an income statement for such fiscal year, a balance sheet of the
Company as of the end of such year and in any event within 120 days thereafter,
and a schedule as to the sources and applications of funds for such year, such
year-end financial reports to be audited by a "Big Six" accounting firm and in
reasonable detail, prepared in accordance with generally accepted accounting
principles ("GAAP");

                (b)  prior to the commencement of each fiscal year of the
Company, an operating budget and updated three year strategic plan; and

                (c)  within thirty (30) days of the end of each month, an
unaudited balance sheet and statement of operations as of the end of such month.

                                      -13-
<PAGE>

          7.2   Inspection Rights. Each Investor shall have the right to visit
                -----------------
and inspect any of the properties of the Company or any of its subsidiaries, and
to discuss the affairs, finances and accounts of the Company or any of its
subsidiaries with its officers, and to review such information as is reasonably
requested all at such reasonable times and as often as may be reasonably
requested; provided, however, that the Company shall not be obligated under this
Section 7.2 with respect to a competitor of the Company or with respect to
information which the Board of Directors determines in good faith is
confidential and should not, therefore, be disclosed.

          7.3   Reservation of Common Stock. The Company will at all times
                ---------------------------
reserve and keep available, solely for issuance and delivery upon the conversion
of the Preferred Stock, all Common Stock issuable from time to time upon such
conversion (the "Conversion Stock").

          7.4   Proprietary Information Agreement. The Company shall require
                ---------------------------------
all employees and consultants to execute and deliver a Proprietary Information
Agreement in the form attached hereto as Exhibit D.
                                         ---------

          7.5   Termination of Information Covenant. The covenant set forth in
                -----------------------------------
Section 7.1 shall terminate as to the Investors and be of no further force or
effect at such time as the initial sale of securities pursuant to a registration
statement filed by the Company under the Securities Act in connection with the
firm commitment underwritten offering of its securities to the general public is
consummated.

          7.6   Key Man Life Insurance. The Company shall obtain and maintain a
                ----------------------
key man life insurance policy for $1,000,000 with respect to the Chief Executive
Officer of the Company with proceeds payable to the Company.

          7.7   Chief Executive Officer Recruitment. The Company shall, within
                -----------------------------------
six months from the date of Closing, engage an executive recruitment firm which
shall conduct a search for a Chief Executive Officer acceptable to the Board of
Directors of the Company.

     8.   Miscellaneous.
          -------------

          8.1   Transfer; Successors and Assigns. The terms and conditions of
                --------------------------------
this Agreement shall inure to the benefit of and be binding upon the respective
successors and assigns of the parties. Nothing in this Agreement, express or
implied, is intended to confer upon any party other than the parties hereto or
their respective successors and assigns any rights, remedies, obligations, or
liabilities under or by reason of this Agreement, except as expressly provided
in this Agreement.

          8.2   Governing Law. This Agreement shall be governed by and
                -------------
construed under the laws of the State of California as applied to agreements
among California residents entered into and to be performed entirely within
California.

                                      -14-
<PAGE>

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

          8.4   Titles and Subtitles. The titles and subtitles used in this
                --------------------
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

          8.5   Notices. Unless otherwise provided, any notice required or
                -------
permitted under this Agreement shall be given in writing and shall be deemed
effectively given upon personal delivery to the party to be notified or upon
deposit with the United States Post Office, by registered or certified mail,
postage prepaid and addressed to the party to be notified at the address or
addresses indicated for such party on Exhibit A hereto, or at such other address
                                      ---------
or addresses as such party may designate by ten (10) days' advance written
notice to the other parties.

          8.6   Finder's Fee. Except as elsewhere disclosed in this Agreement,
                ------------
or  in Exhibit C hereto, each party represents that it neither is nor will be
         ---------
obligated for any finder's fee or commission in connection with this
transaction. The Investor agrees to indemnify and to hold harmless the Company
from any liability for any commission or compensation in the nature of a
finder's fee (and the costs and expenses of defending against such liability or
asserted liability) for which the Investor or any of its officers, employees, or
representatives are responsible.

          The Company agrees to indemnify and hold harmless the Investor from
any liability for any commission or compensation in the nature of a finder's fee
(and the costs and expenses of defending against such liability or asserted
liability) for which the Company or any of its officers, employees or
representatives is responsible.

          8.7   Expenses. If any action at law or in equity is necessary to
                --------
enforce or interpret the terms of this Agreement, the prevailing party shall be
entitled to reasonable attorney's fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

          8.8   Amendments and Waivers. Any term of this Agreement may be
                ----------------------
amended and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively), only with the written consent of the Company and a majority-in-
interest of the Investors.

          8.9   Severability. If one or more provisions of this Agreement are
                ------------
held to be unenforceable under applicable law, such provision shall be excluded
from this Agreement and the balance of the Agreement shall be interpreted as if
such provision were so excluded and shall be enforceable in accordance with its
terms.

          8.10  Entire Agreement. This Agreement constitutes the entire
                ----------------
agreement between the parties hereto pertaining to the subject matter hereof,
and any and all other written or oral agreements existing between the parties
hereto are expressly canceled.

                                      -15-
<PAGE>

          8.11  Exculpation Among Investors. Each Investor acknowledges that it
                ---------------------------
is not relying upon any person, firm or corporation, other than the Company and
its officers and directors, in making its investment or decision to invest in
the Company. Each investor agrees that no Investor nor the respective
controlling persons, officers, directors, partners, agents or employees of any
Investor shall be liable for any action heretofore or hereafter taken or omitted
to be taken by any of them in connection with the Shares.


                 (Remainder of page left intentionally blank)

                                      -16-
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.

INVENTA CORPORATION


By: /s/ Ashok K. Santhanam
    ------------------------------
     Ashok K. Santhanam, President

Address:
2620 Augustine Drive, Suite 225
Santa Clara, CA  95054


INVESTORS:

Battery Ventures L.P.


By: /s/ Todd A. Dagres
    ------------------------------
Name:   Todd A. Dagres
Title:  General Partner

BOSTON MILLENNIA PARTNERS
LIMITED PARTNERSHIP
By:   Glen Partners Limited Partnership,
      its General Partner

By: /s/ Martin J. Hernon
    ------------------------------
    General Partner


/s/ Stephen T. Barry
-----------------------------------
Stephen T. Barry


/s/ A. Dana Callow, Jr.
-----------------------------------
A. Dana Callow, Jr.


/s/ Christian Dubiel
-----------------------------------
Christian Dubiel
<PAGE>

/s/ Martin J. Hernon
----------------------------------
Martin J. Hernon


/s/ Robert W. Jevon
----------------------------------
Robert W. Jevon


/s/ Frank P. Pinto
----------------------------------
Frank P. Pinto


/s/ Suresh Shanmugham
----------------------------------
Suresh Shanmugham


/s/ Bruce R. Tiedemann
----------------------------------
Bruce R. Tiedemann


/s/ Harry A. Caunter
----------------------------------
Harry A. Caunter


/s/ Maya S. Hattangady
----------------------------------
Maya S. Caunter


/s/ Santhanam C. Shekar
----------------------------------
Santhanam C. Shekar

TCV II (Q), L.P.
a Delaware Limited Partnership
By:   Technology Crossover Management II, L.L.C.,
Its:  General Partner

By:_______________________________
     Name: Robert C. Bensky
     Title: Chief Financial Officer

                                      -18
<PAGE>

TCV II Strategic Partners, L.P.
a Delaware Limited Partnership
By:   Technology Crossover Management II, L.L.C.,
Its:  General Partner

By:/s/ Robert C. Bensky
----------------------------------
      Name:  Robert C. Bensky
      Title: Chief Financial Officer

TCV II, V.O.F.
a Netherlands Antilles General Partnership
By:   Technology Crossover Management II, L.L.C.,
Its:  Investment General Partner

By:/s/ Robert C. Bensky
----------------------------------
      Name:  Robert C. Bensky
      Title: Chief Financial Officer

Technology Crossover Ventures II, C.V.
a Netherlands Antilles Limited Partnership
By:   Technology Crossover Management II, L.L.C.,
Its:  Investment General Partner

By:/s/ Robert C. Bensky
----------------------------------
      Name: Robert C. Bensky
      Title: Chief Financial Officer

Technology Crossover Ventures II, L.P.
a Delaware Limited Partnership
By:   Technology Crossover Management II, L.L.C.,
Its:  General Partner

By:/s/ Robert C. Bensky
----------------------------------
      Name: Robert C. Bensky
      Title: Chief Financial Officer


                                     -19-