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                                                                    Exhibit 10.6



                     LIGHT HOUSE CAPITAL PARTNERS II, L.P.


                               Lease Documentation


                                Table of Contents



Tab

1.      Master Equipment Lease Agreement No. 219 dated May 5, 1999

2.      Lease Line Schedule No. 01 dated May 5, 1999

3.      Software Rider dated May 5, 1999

                Software License Assignment Agreement

4.      Equipment Schedules with Summaries to Lease Line Schedule No. 01

                Equipment Schedule No. 01 dated May 5, 1999

                Equipment Schedule No. _____ dated ____________________

                Equipment Schedule No. _____ dated ____________________

                Equipment Schedule No. _____ dated ____________________

5.      Preferred Stock Purchase Warrant


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                        MASTER EQUIPMENT LEASE AGREEMENT
                      Agreement No. 219 Dated: May 5, 1999



LESSOR:       LIGHTHOUSE CAPITAL PARTNERS II, L.P., a Delaware limited
              partnership ("Lessor"), 100 Drakes Landing Road, Suite 260,
              Greenbrae, California 94904-3121

LESSEE:       CHEMCONNECT, INC., a Delaware corporation ("Lessee")

ADDRESS: 44   Montgomery Street, Suite 250, San Francisco, California 94104


        IN CONSIDERATION of the mutual covenants contained herein, the parties
agree as follows:

        1. LEASE. Lessor leases to Lessee and Lessee leases from Lessor the
personal property described in each Equipment Schedule executed pursuant hereto,
subject to the terms and conditions of this Master Equipment Lease Agreement
("Master Lease") and the applicable Lease Line Schedule (defined below). The
"Equipment" (as defined in the Lease Line Schedule) is being leased for
commercial or business purposes only, and not for personal, home, or family
purposes. The parties agree that each Lease is a "finance lease" under the
Uniform Commercial Code (as in effect in the State of California during the term
of the Lease and referred to hereafter as the "UCC").

        2. LEASE LINE SCHEDULE. "Lease Line Schedule" means a Lease Line
Schedule in the form of EXHIBIT A, signed by Lessor and Lessee and incorporating
by reference the terms and provisions of this Master Lease.

        3. EQUIPMENT SCHEDULES. "Equipment Schedule" means an Equipment Schedule
in the form of EXHIBIT B, signed by Lessor and Lessee and incorporating, by
reference, the terms and provisions of this Master Lease and the applicable
Lease Line Schedule. Each Equipment Schedule shall constitute a separate and
independent lease (a "Lease"); the original of such Lease shall consist of the
signed Equipment Schedule and a copy of the Master Lease and applicable Lease
Line Schedule. Capitalized terms used, but not defined, in this Master Lease
have the meanings given to such terms in the applicable Lease Line Schedule or
Equipment Schedule, as the case may be.

        4. TERM AND RENTALS.

           (a) ACCEPTANCE. The Lease shall commence with respect to Equipment
described on the Equipment Schedule upon the Acceptance Date. The "Acceptance
Date" shall be the date upon which Lessee executes a Delivery and Acceptance
Certificate in the form of EXHIBIT C.

           (b) TERM AND PAYMENT OF RENT. The lease term for the Equipment shall
be the "Lease Term" set forth in the Equipment Schedule which shall commence on
the "Commencement Date" (as defined in the Lease Line Schedule). Lessee agrees
to pay to Lessor the "Rental Payments" for the Lease Term, in the amounts and at
the times set forth in the Equipment Schedule.

           (c) INTERIM PERIOD. If the Acceptance Date does not fall on the
Commencement Date, then Lessee agrees to pay to Lessor "Interim Rent" for the
period commencing on the Acceptance Date through and including the day preceding
the Commencement Date (the "Interim Period"). The Interim Rent payment for the
Interim Period shall accrue at the "Interim Rate" (as defined in the Lease Line
Schedule) and shall be due and payable in full on the Commencement Date.

           (d) LEASE TERMINATION. Lessee may terminate the Lease at the
expiration of the Lease Term or any renewal term (the "Lease Termination") by
submitting to Lessor a Notice of Election in the form of EXHIBIT D. If a Notice
of Election is not submitted by Lessee to Lessor during the "Advance Notice
Period" (as defined in the Lease Line Schedule), then the Lease Term or any
renewal Term will be automatically extended for an additional period equal to
the "Automatic Extension Period" (as defined in the Lease Line Schedule). The
Lease will continue to automatically extend until Lessee submits to Lessor a
Notice of Election. The Lease may only be terminated as


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expressly provided in this Section, in the applicable Lease Line Schedule or in
the applicable Equipment Schedule. Lessee agrees to continue paying rent for the
Equipment in the amount of the Rental Payment set forth in the Equipment
Schedule until the later of (i) the expiration of the Lease Term, any renewal
term and any Automatic Extension Period and (ii) either (A) the purchase option
price is paid pursuant to SECTION 6(a), or (B) a mutually agreed renewal of the
Lease takes effect pursuant to SECTION 6(b), or (C) the Equipment is returned in
the manner and condition prescribed in SECTION 6(c), in each case after delivery
of a Notice of Election.

           (e) NET LEASE. Each Equipment Schedule shall be a net lease, and
Lessee's obligation to pay all rent and other sums thereunder shall be absolute
and unconditional, and shall not be subject to any abatement, reduction,
set-off, defense, counterclaims, interruption, deferment or recoupment, for any
reason whatsoever.

        5. LATE FEE. Lessee shall pay a late charge on any rent payments or
other sums due hereunder which are past due, in the amount specified in the
Lease Line Schedule, payable on demand. In addition, interest shall accrue daily
at the "Default Rate" (as defined in the Lease Line Schedule), or if such rate
exceeds the maximum rate allowed by law, then at such maximum rate, and shall be
payable on demand.

        6. LEASE TERMINATION OPTIONS. Upon Lease Termination, Lessee will have
the option to purchase the Equipment, renew the term of the Lease, or return the
Equipment to Lessor, as set forth below. Lessee shall specify its election of a
Lease Termination Option in the Notice of Election.

           (a) PURCHASE OPTION. If Lessee exercises the option to purchase,
then, provided no Event of Default has occurred and is then continuing, Lessee
shall at the expiration of the Lease Term, renewal term or extension, as the
case may be, purchase the Equipment. The purchase price shall be the Equipment's
then fair market value ("FMV"). FMV, as applied to a purchase option, shall be
determined by Lessor based on the price a willing buyer would pay and a willing
seller would accept (neither buyer nor seller being under compulsion to act) for
the Equipment as installed and in use, giving due consideration to its
condition, utility, revenue-producing capability, and replacement costs. If
Lessee fails to agree with Lessor's good faith determination of the FMV, Lessee
shall nevertheless pay Lessor's invoice and provide Lessor with a written
request for a determination of the FMV with or prior to such payment. Within ten
(10) days after such request Lessor and Lessee shall agree on an appraiser to
determine the FMV or, lacking such agreement, shall each tender the name of an
appraiser. The appraiser(s) shall, within thirty (30) days, either agree on the
FMV or select a third appraiser, to form a committee to determine the FMV.
Determination by the appraiser(s) shall be final and binding on both parties.
Within fifteen (15) days after such determination, Lessor shall refund any
excess received over the FMV, and/or Lessee shall pay any additional amount of
the FMV above the amount previously paid. Each party shall bear the fees and
expenses of any appraiser which it names and share equally the fees and expenses
of any appraiser(s) jointly selected. If the appraised FMV is within 5% of the
amount invoiced by Lessor, then Lessee shall pay all appraiser fees and
expenses. The purchase option price shall be paid not later than the last day of
the Lease Term.

           (b) RENEWAL. If Lessee exercises the option to renew this Lease, such
renewal shall be upon the terms and conditions of this Master Lease and the
applicable Lease Line Schedule, for a rental period and rental amount to be
agreed upon by Lessee and Lessor.

           (c) RETURN. If the Notice of Election specifies return of the
Equipment, Lessee at its own risk and expense (i) will immediately return the
Equipment to Lessor in the same condition as when delivered, ordinary wear and
tear excepted, at such location as Lessor shall designate provided, however,
that Lessee's expense shall be limited to the cost of returning the Equipment
(including expenses relating to the provision of insurance) to Lessor's address
as set forth herein; and (ii) will, on request from Lessor, use best efforts to
obtain from the Equipment supplier (or other maintenance service supplier
approved by Lessor) a certificate stating that the Equipment qualifies for
continued maintenance service at the standard rates and terms then in effect.

        7. USE; MAINTENANCE.

           (a) Lessee, at its expense, shall make all necessary site
preparations and cause the Equipment to be operated in accordance with any
applicable operating manuals and manufacturer's instructions. Notwithstanding
any transfer or assignment by Lessor and provided that no Event of Default
exists hereunder, Lessee shall have the



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right to quietly possess and use the Equipment as provided herein without
interference by Lessor, its assigns or any other third party claiming through or
under Lessor.

           (b) Lessee shall effect and bear the expense of all necessary repair,
maintenance, operation and replacements required to be made to maintain the
Equipment in good condition, reasonable wear and tear excepted, and to comply
with all domestic and international laws to which the use and operation of the
Equipment may be or become subject, except to the extent that failure to comply
would not have an adverse effect on the Equipment or Lessor's rights hereunder.
All replacement Equipment and parts furnished in connection with such
maintenance or repair shall immediately become the property of Lessor and part
of the Equipment for all purposes hereof. All such maintenance, repair and
replacement services shall be immediately paid for and discharged by Lessee with
the result that no lien under any applicable laws will attach to the Equipment
as a result of the performance of such services or the provision of any such
material which is enforceable by the holder thereof, except for liens that are
being contested in good faith by proceedings that are being diligently pursued
and for which adequate reserves in accordance with generally accepted accounting
principles have been created.

        8. INSURANCE. Lessee shall obtain and maintain for the Lease Term (and
any renewal term or extension), at its own expense, (a) "all risk" insurance
against loss or damage to the Equipment, (b) commercial general liability
insurance (including contractual liability, products liability and completed
operations coverage) reasonably satisfactory to Lessor, and (c) such other
insurance against such other risks of loss and with such terms, as shall in each
case be reasonably satisfactory to or reasonably required by Lessor (as to
carriers, amounts and otherwise). The amount of the "all risk" insurance shall
be greater than or equal to the Stipulated Loss Value (as defined in SECTION 9
below) of all Equipment outstanding under the Lease Line Schedule, and must
otherwise be reasonably satisfactory to Lessor as of each anniversary date of
this Lease. Any increase in the amount of such insurance coverage, other than
"all risk", reasonably requested by Lessor shall be put into effect on the next
succeeding renewal date of such insurance.

        Each "all risk" policy shall: (i) name Lessor as sole loss payee with
respect to the Equipment, (ii) provide for each insurer's waiver of its right of
subrogation against Lessor and Lessee, and (iii) provide that such insurance
shall not be invalidated by any action of, or breach of warranty by, Lessee of a
provision of any of its insurance policies, and shall waive set-off,
counterclaim or offset against Lessor.

        Each liability policy shall name Lessor as an additional insured and
provide that such insurance shall have cross-liability and severability of
interest endorsements (which shall not increase the aggregate policy limits of
Lessee's insurance).

        All insurance policies shall provide that Lessee's insurance shall be
primary without a right of contribution of Lessor's insurance, if any, or any
obligation on the part of Lessor to pay premiums of Lessee, and shall contain a
clause requiring the insurer to give Lessor at least 30 days' prior written
notice of its cancellation (other than cancellation for non-payment for which 10
days' notice shall be sufficient). Lessee shall on or prior to the date of
Equipment Schedule No. 01 and prior to each policy renewal, furnish to Lessor
certificates of insurance or other evidence satisfactory to Lessor that such
insurance coverage is in effect. Lessee further agrees to give Lessor prompt
notice of any damage to, or loss of, the Equipment, or any part thereof.

        9. LOSS OR DAMAGE. If any items of Equipment shall become lost, stolen,
destroyed, or damaged beyond repair for any reason, or in the event of
condemnation, confiscation, seizure or requisition of title to or use of such
items (collectively, an "Event of Loss"), Lessee shall, subject to the second
paragraph of this SECTION 9, promptly pay to Lessor the applicable Stipulated
Loss Value of the Equipment subject to the Event of Loss. Upon payment by Lessee
of the Stipulated Loss Value, Lessor will transfer to Lessee, "AS IS, WHERE IS,
WITHOUT RECOURSE, REPRESENTATION OR WARRANTY," all of Lessor's right, title and
interest, if any, in such items of Equipment. The "Stipulated Loss Value"
payable by Lessee under this Lease shall be an amount equal to the product of
(a) Lessor's Cost of the affected Equipment and (b) the percentage set forth in
the table attached to the applicable Lease Line Schedule as ANNEX A opposite the
Rental Payment number next following the Event of Loss. Stipulated Loss Values
and Rental Payments shall not be prorated.

Notwithstanding any other provision hereof, Lessee shall have the right to
replace an item of Equipment that is the subject of an Event of Loss, with a
replacement item of Equipment (the "Replacement Equipment") reasonably



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acceptable to Lessor, rather than pay the applicable Stipulated Loss Value of
such Equipment, provided that all of the following conditions precedent are
satisfied (i) no Event of Default has occurred and is continuing, (ii) Lessee
conveys to Lessor good title to the Replacement Equipment free and clear of all
liens and encumbrances, (iii) Lessee executes and delivers bills of sale, lease
supplements and such other documents relating to the Replacement Equipment that
Lessor reasonably determines are necessary to transfer title to the Replacement
Equipment to Lessor and to give notice of or to perfect Lessor's rights, title
and interest therein, (iv) the Replacement Equipment is in as good condition and
has the same fair market value and residual value, utility, and remaining useful
life as the Equipment being replaced, and (v) Lessee indemnifies Lessor against
any adverse tax consequences relating to such replacement.

        10. TITLE, INSPECTION AND LOCATION.

            (a) TITLE. Lessor and Lessee confirm their intent that title to the
Equipment shall remain in Lessor (or its successors and assigns) exclusively. If
requested by Lessor, Lessee will affix plates or markings on the Equipment and
on any operating manuals and manufacturer's instructions indicating the
interests of Lessor and its assigns therein, and Lessee will not allow any other
indicia of ownership or other interest in the Equipment to be placed on the
Equipment. Lessee shall not sell, assign, grant a security interest in, sublet,
pledge, hypothecate or otherwise encumber or suffer a lien upon or against this
Lease or the Equipment.

            (b) INSPECTION. Lessor (through any of its officers, employees or
agents) shall have the right to inspect the Equipment during regular business
hours, with reasonable notice, and in compliance with Lessee's reasonable
security procedures; provided, that such inspections will be conducted no more
often then once every six (6) months unless an Event of Default, or event which,
with notice or lapse of time or both, would become an Event of Default, has
occurred and is continuing.

            (c) LOCATION. In the case of Equipment other than mobile Equipment,
Lessee may move such Equipment from the installation address shown on the
Equipment Schedule (or any other location for which Lessee has complied with
this provision) only if (i) the new location is within the continental United
States, and (ii) Lessee gives at least 30 days' prior written notice of the
relocation and provides UCC financing statements, landlord waivers or such other
documentation as Lessor reasonably requests to protect its interest in the
Equipment. In the case of mobile equipment (including, without limitation,
lap-top computers), Lessee agrees to obtain from the person using such mobile
Equipment and deliver to Lessor, an Acknowledgment in the form of EXHIBIT F.

            (d) Lessee shall keep copies of all operating manuals and
manufacturer's instructions with respect to the Equipment in good condition at
the locations specified in SECTION 10(c).

        11. LESSEE'S REPRESENTATIONS, WARRANTIES AND WAIVERS. Upon execution of
the Master Lease and each Equipment Schedule, Lessee warrants and represents the
following:

            (a) Lessee is a corporation duly organized, validly existing and in
good standing under the laws of its state of incorporation. Lessee has full
power and authority and all necessary licenses and permits to carry on its
business as presently conducted, to own or hold under lease its properties and
to enter into this Master Lease, the Lease Line Schedule and each Equipment
Schedule and to perform its obligations thereunder; and Lessee is duly qualified
to do business as a foreign corporation and is in good standing in each
jurisdiction in which the character of its properties or the nature of its
business or the performance of its obligations under this Master Lease, the
Lease Line Schedule and any Equipment Schedule requires such qualification,
except for such jurisdictions in which failure to qualify would not have a
material adverse effect on Lessee.

            (b) The execution and delivery by Lessee of this Master Lease, the
Lease Line Schedule and each Equipment Schedule and the performance by Lessee of
its obligations thereunder have been duly authorized by all necessary corporate
action on the part of Lessee; and do not and will not contravene the provisions
of, or constitute a default (either with or without notice or lapse of time, or
both) under, or result in the creation of any lien upon, the Equipment or any
property of Lessee under any indenture, mortgage, contract or other instrument
to which Lessee is a party or by which Lessee or its properties is bound.





                                       4.
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            (c) No consent or approval of, giving of notice to, registration
with, or taking of any other action by, any state, federal, foreign or other
governmental commission, agency or regulatory authority or any other person or
entity is required for the consummation or performance by Lessee of the
transactions contemplated under this Master Lease, the Lease Line Schedule and
each Equipment Schedule.

            (d) This Master Lease, the Lease Line Schedule and each Equipment
Schedule, when executed by Lessee, constitute legal, valid and binding
agreements of Lessee enforceable against Lessee in accordance with their terms,
except as limited by any bankruptcy, insolvency, reorganization, or other
similar laws of general application affecting the enforcement of creditor or
Lessor rights and general principles of equity.

            (e) There are no actions, suits or proceedings pending or threatened
against or affecting Lessee or any property of Lessee in any court, before any
arbitrator of any kind or before or by any federal state, municipal or other
government department, commission, board, bureau, agency or instrumentality
(collectively "Governmental Body"), which, if adversely determined, would
materially adversely affect the business, financial condition, assets, or
operations of Lessee, or adversely affect the ability of Lessee to perform its
obligations under this Master Lease, the Lease Line Schedule and each Equipment
Schedule; and Lessee is not in default with respect to any order of any court,
arbitrator or Governmental Body or with respect to any material loan agreement,
debt instrument or contract with a supplier or customer of Lessee, except as
disclosed in writing to Lessor.

            (f) To the extent permitted by applicable law, Lessee waives any and
all rights and remedies to: (i) cancel this Lease; (ii) repudiate this Lease;
(iii) reject the Equipment; (iv) revoke acceptance of the Equipment; (v) recover
damages from Lessor for any breaches of warranty or for any other reason; (vi)
claim a security interest in the Equipment in Lessee's possession or control for
any reason; (vii) deduct from Rental Payments all or any part of any claimed
damages resulting from Lessor's default, if any, under this Lease; (viii) accept
partial delivery of the Equipment; (ix) "cover" by making any purchase or lease
of or contract to purchase or lease equipment in substitution for Equipment
designated in the Lease; (x) recover any direct, general, special, incidental,
indirect, exemplary or consequential damages, for any reason whatsoever; and
(xi) obtain specific performance, replevin, detinue, sequestration, claim and
delivery or the like for any Equipment identified to this Lease. To the extent
permitted by applicable law, Lessee also waives any rights now or hereafter
conferred by statute or otherwise which may require Lessor to sell, lease or
otherwise use any Equipment in mitigation of Lessor's damages or which may
otherwise limit or modify any of Lessor's rights or remedies.

        12. ASSIGNMENT BY LESSOR. LESSEE ACKNOWLEDGES THAT LESSOR MAY SELL,
ASSIGN, GRANT A SECURITY INTEREST IN, OR OTHERWISE TRANSFER ALL OR ANY PART OF
ITS RIGHTS, TITLE AND INTEREST IN THIS LEASE AND THE EQUIPMENT WITHOUT NOTICE TO
OR CONSENT OF LESSEE. Upon Lessor's written notice to Lessee that this Lease, or
the right to the Rental Payments hereunder, have been assigned, Lessee shall, if
requested, pay directly to Lessor's assignee without abatement, deduction or
set-off all amounts which become due hereunder. Lessee waives and agrees it will
not assert against Lessor's assignee any counterclaim or set-off in any action
for rent under this Lease. Upon the assignment of this Lease, Lessor's assignee
shall have and be entitled to exercise any and all rights and remedies (but none
of the obligations) of Lessor hereunder, and all references herein to Lessor
shall include Lessor's assignee. Lessee acknowledges that any assignment or
transfer by Lessor does not materially change Lessee's duties or obligations
under this Lease nor materially increase the burdens or risks imposed on Lessee.

        13. ASSIGNMENT BY LESSEE. LESSEE MAY NOT, WITHOUT LESSOR'S PRIOR WRITTEN
CONSENT, (i) ASSIGN THIS LEASE, WHETHER BY OPERATION OF LAW OR OTHERWISE, OR
SUBLEASE THE EQUIPMENT OR ANY PART THEREOF OR (ii) ASSIGN, GRANT A SECURITY
INTEREST IN, OR OTHERWISE TRANSFER ALL OR ANY PART OF ITS RIGHTS, TITLE AND
INTEREST IN AND TO THIS LEASE OR THE EQUIPMENT. In the event Lessee makes an
assignment, sublease or other transfer (to which Lessor has consented), Lessee
shall not thereby be relieved of its duties and obligations hereunder, for which
it shall remain fully responsible and liable (independent of its assignee).

Notwithstanding the foregoing, in the event of a merger, sale of substantially
all of the assets or other reorganization involving Lessee in which the
shareholders of Lessee immediately prior to such transaction own less than 50%
of the voting securities of the surviving entity or purchaser of assets (or its
parent) in such transaction, Lessor shall not



                                       5.
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withhold its consent to the assignment of this Lease to the successor entity if
each of the following conditions precedent is satisfied:

        (i) the successor entity as of the date of such assignment meets
Lessor's then current credit standards, as determined by Lessor in Lessor's sole
reasonable judgment;

        (ii) Lessee gives Lessor at least thirty (30) days prior written notice
of such merger, sale of assets or other reorganization;

        (iii) such merger, sale of assets or other reorganization does not
adversely affect the rights of Lessor;

        (iv) the corporation that results from such merger or other
reorganization or which purchases the assets in the case of a sale of assets
(the "Surviving Corporation") shall have executed and delivered to Lessor an
agreement in form and substance reasonably satisfactory to Lessor, containing an
assumption by Surviving Corporation of the due and punctual performance and
observance of each covenant and condition of Lessee in the Master Lease, Lease
Line Schedule and Equipment Schedules (the "Lease Documents") and making
representations and warranties with respect to the Surviving Corporation similar
in scope and substance to the representations and warranties made by Lessee in
the Lease Documents;

        (v) the Surviving Corporation executes any precautionary financing
statements or amendments thereto reasonably requested by Lessor; and

        (vi) immediately after giving effect of such merger, sale of assets or
other reorganization, no Event of Default or, event which with the lapse of time
or giving of notice or both, would result in an Event of Default shall have
occurred and be continuing.

        14. TAXES.

            (a) Lessee shall comply with all applicable federal, state, local,
foreign and international laws, regulations and orders relating to this Lease.
Lessee assumes liability for, and shall pay when due, and on a net after-tax
basis shall indemnify and defend Lessor against, all federal, state, local,
foreign and international fees, taxes and government charges (including, without
limitation, interest and penalties) of any nature imposed upon or in any way
relating to Lessor, Lessee, any item of Equipment or this Lease, except federal,
state and local taxes on or measured by Lessor's net income (other than any such
tax which is in substitution for or relieves Lessee from the payment of taxes it
would otherwise be obligated to pay to or reimburse Lessor for as herein
provided). Lessee shall at its expense file when due with the appropriate
authorities any and all tax and similar returns and reports required to be filed
with respect thereto or, if requested by Lessor, notify Lessor of all such
requirements and furnish Lessor with all information required for Lessor to
effect such filings, which filings shall also be at Lessee's expense. Any fees,
taxes or other charges paid by Lessor upon failure of Lessee to make such
payments shall at Lessor's option become immediately due from Lessee to Lessor.

            (b) This Lease has been entered into on the assumption that Lessor
shall be entitled to all deductions, credits, and other tax benefits as are
provided in the Internal Revenue Code of 1986, including amendments as may occur
(the "Code"), to an owner of property including, without limitation,
depreciation deductions and interest deductions with respect to any debts
incurred to finance the purchase of the Equipment. If, as a result of any acts,
omissions or misrepresentations by Lessee, Lessor's projected after-tax economic
return resulting from ownership and lease of the Equipment is reduced, then
Lessee's Rental Payments shall be increased in an amount (based on Lessor's
reasonable calculations) sufficient to provide the same net after-tax economic
return as if such acts or omissions or changes had not occurred. Appropriate
increases shall also be made in the applicable Stipulated Loss Values for this
Lease. In the event the Equipment is sold by Lessor to another party, the net
after-tax economic returns considered shall be those of such other party.

        15. EQUIPMENT WARRANTIES. Lessee acknowledges that (i) Lessee has
selected the supplier of the Equipment, (ii) Lessor acquired the goods or the
right to possession and use of the goods in connection with the Lease, and (iii)
Lessee received a copy of the contract by which Lessor acquired the Equipment or
the right to possession and use of the Equipment before signing the Lease.
LESSOR MAKES NO EXPRESS OR IMPLIED




                                       6.
<PAGE>   8


WARRANTIES INCLUDING THOSE OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE
WITH RESPECT TO THE EQUIPMENT AND DISCLAIMS THE SAME. Lessor shall have no
liability for any damages, whether direct, indirect, general, special,
incidental, exemplary or consequential, incurred by Lessee as a result of any
defect or malfunction of the Equipment. Lessee shall look solely to the
Equipment supplier for any and all claims related to the Equipment. Lessor
assigns to Lessee, for and during the Lease Term, any warranty on the Equipment
provided by the supplier. Lessor and Lessee agree that all limitations on
remedies and liability contained in this Lease represent a reasonable allocation
of risks that is part of the fundamental bargain between the parties.

        16. EVENTS OF DEFAULT. An Event of Default shall occur if Lessee (i)
fails to pay any Rental Payment or other payment required under the Lease when
due and such failure continues for a period of five (5) days after written
notice from Lessor; or (ii) fails to perform or observe any other covenant,
condition or agreement to be performed or observed by it or breaches any
provision contained in the Lease or in any other document furnished to Lessor in
connection herewith, and such failure or breach continues for a period of thirty
(30) days after written notice from Lessor; or (iii) without Lessor's consent,
attempts to assign this Lease or sell, transfer, encumber, part with possession,
or sublet any item of Equipment; or (iv) makes any representation or warranty
herein or in any document furnished by Lessee in connection herewith, which
shall have been materially false or inaccurate when made or at the time to which
such representation or warranty relates; or (v) shall commit an act of
bankruptcy or become insolvent or bankrupt or make an assignment for the benefit
of creditors or consent to the appointment of a Trustee or Receiver or either
shall be appointed for Lessee or for a substantial part of its property without
its consent, or bankruptcy reorganization, or insolvency proceedings shall be
instituted by or against Lessee, and, if instituted against Lessee, shall not be
vacated or dismissed within sixty (60) days. Any Event of Default shall be
deemed material and a substantial impairment of Lessor's interests for the
purposes of this Lease, the UCC, and any other applicable law.

        17. REMEDIES. Upon the occurrences of any Events of Default and at any
time thereafter, provided such Event of Default is then continuing, Lessor may,
in its discretion, do any one or more of the following:

            (a) cancel any or all Leases which reference this Master Lease or
the Lease Line Schedule, upon notice to Lessee;

            (b) recover any accrued and unpaid Rental Payments and other amounts
which are due and owing under the Leases so canceled on the Rental Payment Date
immediately preceding the date on which Lessor obtains possession of the
Equipment (or such earlier date as judgment is entered in favor of Lessor) (the
"Determination Date"), plus interest at the Default Rate;

            (c) with or without canceling this Lease, recover such Stipulated
Loss Value as of the Rental Payment Date immediately preceding the Determination
Date;

            (d) recover any amounts due under any indemnity then determinable,
plus interest at the Default Rate;

            (e) require that Lessee provide the return and certification of the
Equipment in accordance with SECTION 6(c) hereof;

            (f) enter the premises where such Equipment is located and take
immediate possession of and remove the same, all without liability to Lessor or
its agents for such entry;

            (g) sell any or all of the Equipment at public or private sale, with
or without notice to Lessee or advertisement, or otherwise dispose of, hold,
use, operate, lease to others or keep idle such Equipment, all free and clear of
any rights of Lessee with the exception of providing Lessee, upon written
request, an accounting of the proceeds with respect thereto; and

            (h) exercise any other right or remedy which may be available to it
under the UCC or other applicable law including the right to recover damages for
the breach hereof.



                                       7.

<PAGE>   9


        In addition, Lessee shall be liable for, and reimburse Lessor for, all
reasonable legal fees and all commercially reasonable costs and expenses
incurred by Lessor as a result of the foregoing defaults or the exercise of
Lessor's remedies, including without limitation recovering possession of the
Equipment, selling or leasing the Equipment (including broker's and sales
representative's fees and commissions), and placing any Equipment in the
condition and obtaining the certificate required by SECTION 6(c) hereof. No
remedy referred to in this Section is intended to be exclusive, but each shall
be cumulative and in addition to any other remedy referred to above or otherwise
available to Lessor at law or in equity. No express or implied waiver by Lessor
of any default shall constitute a waiver of any other default by Lessor, or a
waiver of any of Lessor's rights.

        18. INDEMNIFICATION. Lessee assumes liability for, and shall pay when
due, and shall indemnify, reimburse and hold each Indemnified Person (defined
below) harmless from and against all Claims (defined below), directly or
indirectly relating to or arising out of the acquisition, use, manufacture,
purchase, shipment, transportation, delivery, installation, lease or sublease,
ownership, operation, possession, control, storage, return or condition of any
item of Equipment (regardless of whether such item of Equipment is at the time
in the possession of Lessee), the falsity of any non-tax representation or
warranty of Lessee or Lessee's failure to comply with the terms of the Lease
during the Lease Term. The foregoing indemnity shall cover, without limitation,
(i) any Claim in connection with a design or other defect (latent or patent) in
any item of Equipment, (ii) any Claim for infringement of any patent, copyright,
trademark or other intellectual property right, or (iii) any Claim for
negligence or strict or absolute liability in tort; provided, however, that
Lessee shall not indemnify any Indemnified Person for any liability to the
extent it results from such Indemnified Person's gross negligence or willful
misconduct.

        "Claim" means all liabilities, losses, damages, actions, suits, demands,
claims of any kind and nature (including, without limitation, claims relating to
environmental discharge, cleanup or compliance), and all costs and expenses
whatsoever to the extent they may be incurred or suffered by an Indemnified
Person in connection therewith (including, without limitation, reasonable
attorneys' fees and expenses), fines, penalties (and other charges of applicable
governmental authorities), licensing fees relating to any item of Equipment,
damage to or loss of use of property (including, without limitation,
consequential or special damages to third parties or damages to Lessee's
property), or bodily injury to or death of any person (including, without
limitation, any agent or employee of Lessee).

        "Indemnified Person" means Lessor (including without limitation, each of
its partners) and each of their respective successors, assigns, agents,
officers, directors, shareholders, partners, servants, agents and employees.

        Such indemnities shall continue in full force and effect,
notwithstanding the expiration or termination of this Lease. Upon Lessor's
written demand, Lessee shall assume and diligently conduct, at its sole cost and
expense, the entire defense of any Indemnified Person against any indemnified
Claim described in this SECTION 18. Lessor may not enter into any settlement or
other compromise with respect to any Claim covered by the indemnity set forth in
this SECTION 18 without Lessee's prior written consent, which shall not be
unreasonably withheld, conditioned or delayed, and if a claim is settled or
compromised without such consent, Lessee shall not be obligated to provide
indemnification under this SECTION 18. If any Indemnified Person obtains
recovery of any of the amounts that Lessee has paid to such Indemnified Person
pursuant to the indemnity set forth in this SECTION 18, then such Indemnified
Person shall promptly pay to Lessee the amount of such recovery. Lessee shall
not settle or compromise any Claim against or involving Lessor without first
obtaining Lessor's written consent thereto, which consent shall not be
unreasonably withheld. Lessee shall give Lessor prompt notice of any occurrence,
event or condition in connection with which Lessor may be entitled to
indemnification hereunder. The provisions of this SECTION 18 are in addition to,
and not in limitation of, the provisions of SECTION 14(b).

        19. NOTICES. Any notices or demands required or permitted hereunder
shall be given to the parties in writing and by personal delivery, regular or
certified mail, facsimile or telegram at the address set forth in the Lease Line
Schedule or to such other address as the parties may hereafter substitute by
written notice given in the manner prescribed in this Section. Such notices or
demands shall be deemed given upon receipt in the case of personal delivery and
upon mailing or transmission in the case of mail, facsimile or telegram. Lessee
agrees to provide Lessor with thirty (30) days' prior written notice of (a) any
merger or consolidation with or into any other business organization, (b) any
sale, lease or other disposition of assets not in the ordinary course of
business, and (c) any other material change in Lessee's financial structure or
ownership.



                                       8.

<PAGE>   10

        20. CONFIDENTIALITY. By execution of this Lease, Lessor agrees that, in
addition to any other agreement regarding confidentiality executed by it, Lessor
will not provide or disclose to any third party any confidential information
relating to the Lease or obtained from time to time in connection with the
Lease, or relating to Lessee or its business, business prospects or affairs,
except (a) to its own directors, officers, employees, auditors, counsel and
other professional advisors and to its affiliates if Lessor reasonably
determines that any such party should have access to such information; (b) if
such information is generally available to the public; (c) if required or
appropriate in any report, statement or testimony submitted to any governmental
authority having or claiming to have jurisdiction over Lessor; (d) if required
or appropriate in response to any summons or subpoena or in connection with any
litigation, to the extent permitted or deemed advisable by counsel; (e) to
comply with any requirement or law applicable to Lessor; (f) to the extent
necessary in connection with the exercise of any right or remedy under the
Lease; (g) to any participant or assignee of Lessor or any prospective
participant or assignee, provided that such participant or assignee or
prospective participant or assignee agrees in writing to be bound by this
SECTION 20 prior to disclosure, or (h) otherwise with the prior consent of
Lessee; provided, however, that any disclosure made in violation of the Lease
shall not affect the obligations of Lessee under the Lease. Confidential
information means any information, other than information readily available in
the public domain, that is identified to Lessor as confidential or proprietary
or is otherwise reasonably known to Lessor to be information that Lessee would
expect to remain confidential, including without limitation nonpublic financial
information, projections, business plans, customer lists, trade secrets and
other proprietary information. Lessor shall inform any third party to whom it
discloses confidential information that such information is subject to a
confidentiality agreement, provided, however, that failure to do so shall not
affect the obligation of Lessee hereunder and Lessor shall not be responsible
for any action/inaction of said third party.

        21. FURTHER ASSURANCES. Lessee will promptly execute and deliver to
Lessor such further reasonable documents and take such further reasonable action
as Lessor may request in order to more effectively carry out the intent and
purpose of this Lease or an assignment of Lessor's interest herein.

        22. MISCELLANEOUS. This Lease shall be binding upon and inure to the
benefit of the parties hereto, their permitted successors and assigns. Any
provision of the Lease which is unenforceable in any jurisdiction shall, as to
such jurisdiction, be ineffective to the extent of such prohibition or
unenforceability without invalidating the remaining provisions hereof; and any
such prohibition or unenforceability in any jurisdiction shall not invalidate or
render unenforceable such provision in any other jurisdiction; provided,
however, that to the extent that the provisions of any such applicable law can
be waived, they are waived by Lessee. Time is of the essence with respect to the
Lease. The captions set forth herein are for convenience only and shall not
define or limit any of the terms hereof. THIS LEASE SHALL IN ALL RESPECTS BE
GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF
CALIFORNIA, WITHOUT REFERENCE TO CONFLICT OF LAWS PRINCIPLES. LESSOR AND LESSEE
WAIVE ALL RIGHTS TO TRIAL BY JURY IN ANY LITIGATION ARISING FROM THIS LEASE.
THIS LEASE SHALL BECOME EFFECTIVE AND BINDING ON THE PARTIES, THEIR RESPECTIVE
SUCCESSORS AND PERMITTED ASSIGNS, AND SHALL BE DEEMED EXECUTED AND PERFORMED IN
THE STATE OF CALIFORNIA, WHEN THE RELATED EQUIPMENT SCHEDULE IS ACCEPTED BY
LESSOR. LESSEE CONSENTS TO THE NON-EXCLUSIVE JURISDICTION OF THE STATE COURTS OF
CALIFORNIA FOR THE RESOLUTION OF ANY DISPUTES HEREUNDER.




                                       9.

<PAGE>   11


        23. AMENDMENTS, MODIFICATIONS, WAIVERS. NONE OF THE PROVISIONS OF THIS
LEASE MAY BE AMENDED, MODIFIED OR WAIVED EXCEPT IN A WRITING SIGNED BY LESSOR
AND LESSEE.


INITIALS  PJR   (LESSEE)                   INITIALS    RDS    (LESSOR)
        -------                                     ---------



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By: /s/ Philip J. Ringo                    By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.P.,
                                               its general partner


Name:  Phil J. Ringo
      ------------------------------       By: LIGHTHOUSE CAPITAL
Title: President and COO                       PARTNERS, INC.,
       -----------------------------           its general partner


                                           By: /s/ Richard D. Stubblefield
                                              ---------------------------------

                                           Name: Richard D. Stubblefield
                                                 ------------------------------

                                           Title: Managing Director
                                                  -----------------------------




                                       10

<PAGE>   12

                                    EXHIBIT A


     LEASE LINE SCHEDULE NO. 01, dated May 5, 1999 ("Lease Line Schedule"),
                                       to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease"),
                                 by and between
      LIGHTHOUSE CAPITAL PARTNERS II, L.P., a Delaware limited partnership
      ("Lessor") and CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

IN CONSIDERATION of the mutual covenants contained herein, the parties agree as
follows:

        LEASE LINE. The total Lessor's Cost of all units of Equipment under all
Equipment Schedules pursuant to this Lease Line Schedule shall not exceed
$700,000.00 (the "Commitment"). "LESSOR'S COST" means, with respect to a unit of
Equipment, the total cost to Lessor of purchasing such unit, as indicated on the
applicable Equipment Schedule. Lessor's obligation to fund Equipment Schedules
under the Commitment shall terminate on December 31, 1999 (the "Commitment
Termination Date"). The minimum Lessor's Cost for each Delivery & Acceptance
Certificate shall be $10,000.00.

        RENTAL FACTOR. The Rental Factor for each Equipment Schedule will be
2.98% of scheduled Lessor's Cost per month, payable monthly in advance. The
Rental Payment under a particular Equipment Schedule shall be an amount equal to
the product of (a) the Rental Factor and (b) the aggregate Lessor's Cost of
Equipment subject to such Equipment Schedule.

        INTERIM RENT. The daily Interim Rent factor shall be equal to 0.0208%
for each item of Equipment (the "Interim Rate"). The daily Interim Rent payment
shall be an amount equal to the product of (a) 0.0208%, and (b) the Lessor's
Cost for each item of Equipment.

        ADVANCE RENT. On the Commencement Date set forth in each Equipment
Schedule to this Lease Line Schedule, Lessee shall pay to Lessor advance rent
equal to the product of (a) the Rental Factor and (b) the aggregate Lessor's
Cost of Equipment subject to such Equipment Schedule ("Advance Rent"), to be
applied toward the last Rental Payment due from Lessee to Lessor under each
Equipment Schedule.

        EXPENSES. Lessee agrees to reimburse Lessor for up to One Thousand
Dollars ($1,000.00) of expenses incurred in connection with the negotiation and
documentation of this transaction, promptly upon receipt of an invoice.

        ELIGIBLE EQUIPMENT. All equipment to be financed under an Equipment
Schedule must be Eligible Equipment. "Eligible Equipment" means the following
types of equipment to the extent acceptable to Lessor:

        Various new and used computers, peripherals, analytical and test
equipment, laboratory equipment and furniture, office furniture and equipment,
software in an amount not to exceed Two Hundred Ten Thousand Dollars ($210,000),
and other equipment as mutually agreed to by Lessee and Lessor, together with
all replacements, parts, cables, repairs, additions and accessories incorporated
therein or affixed thereto and all operating manuals and manufacturer's
instructions (collectively hereinafter called the "Equipment"). Such
replacements, parts, cables, repairs, additions and accessories shall (whether
or not purchased by Lessor) be considered part of the Equipment for all purposes
and, when installed in or attached to the Equipment (unless otherwise agreed),
be or become the property of the Lessor. Except as otherwise specifically
provided or the context so requires, the term "Equipment" includes operating
system or other bundled software which is delivered on or with the Equipment and
which constitutes an accession that could not be removed upon Lease Termination
without adversely affecting the functionality of Equipment in which it is
installed or is included on the Equipment Schedules. Equipment that is older
than ninety (90) days will be valued at its net book value, provided however,
that with respect to the first Equipment Schedule under this Lease Line,
Equipment that is older than one hundred twenty (120) days will be valued at its
net book value.

        COMMENCEMENT DATE. The "Commencement Date" for each Equipment Schedule
shall be the first day of the calendar month following the Acceptance Date for
the items of Equipment subject to such Equipment Schedule.



                                       1
<PAGE>   13

        LEASE TERMINATION OPTIONS. Upon Lease Termination (as defined in the
Master Lease), Lessee will have, with respect to all but not less than all of
the Equipment governed by this Lease Line Schedule, the option to (a) purchase
the Equipment for the lesser of its then fair market value or twenty percent
(20%) of Lessor's Cost, (b) renew the Lease or (c) return the Equipment to
Lessor as provided in SECTION 6 of the Master Lease.

        ADVANCE NOTICE PERIOD. The "Advance Notice Period" shall be at least
ninety (90) days, but not more than 180 days, prior to Lease Termination (as
defined in the Master Lease) of Equipment Schedule No. 01 to this Lease Line
Schedule.

        AUTOMATIC EXTENSION PERIOD. The "Automatic Extension Period" shall equal
three (3) months and affects each Equipment Schedule under this Lease Line
Schedule.

        INSURANCE. The amount of commercial general liability insurance (other
than products liability coverage and completed operations insurance) required
under the Master Lease shall be at least $2,000,000 per occurrence. The amount
of the products liability and completed operations insurance under the Master
Lease shall be at least $2,000,000 per occurrence.

        FINANCIAL STATEMENTS. Lessee shall deliver to Lessor: (a) as soon as
available, but in any event within twenty (20) days after the end of each month,
a company prepared balance sheet, income statement and cash flow statement
covering Lessee's operations during such period, certified by an officer of
Lessee reasonably acceptable to Lessor; (b) as soon as available, but in any
event within ninety (90) days after the end of Lessee's fiscal year, audited
financial statements of Lessee prepared in accordance with generally accepted
accounting principles, consistently applied, together with an unqualified
opinion (other than a going concern qualification) on such financial statements
of an independent certified public accounting firm reasonably acceptable to
Lessor; (c) promptly upon becoming available, copies of all statements, reports,
budgets, sales projections, operating plans and notices sent or made available
generally by Lessee to its security holders; (d) immediately upon receipt of
notice thereof, a report of any material legal actions pending or threatened
against Lessee; and (e) such other financial information as Lessor may
reasonably request from time to time.

        MAINTENANCE SERVICE CONTRACTS. Lessee shall obtain and keep in effect at
all times during the Lease Term (and any renewal or extension thereof),
maintenance service contracts covering any Equipment with (i) a Lessor's Cost in
excess of $10,000 and/or (ii) Equipment for which maintenance service contracts
are customarily available with the Equipment supplier or with suppliers of
maintenance services approved by Lessor, such approval not to be unreasonably
withheld.

        INSTALLATION, HANDLING AND DELIVERY CHARGES. Any handling and delivery
charge to cover all Equipment transportation, rigging, drayage, packing,
installation and handling to and from vendor's plant and upon return to Lessor's
designated location shall be paid by Lessee.

        MISCELLANEOUS TAXES. Without limitation of the provisions of the Master
Lease, Lessee agrees to pay and to indemnify Lessor for any sales or use tax and
any property tax in connection with the sale, lease or use of the Equipment.

        LATE FEE. Lessee shall pay a late charge on any rent payments or other
sums due hereunder which are more than ten (10) days past due, in an amount
equal to 2% of the past due amount, payable on demand.

        DEFAULT RATE. The Default Rate of interest on late payments shall be
eighteen percent (18%) per annum.

        NOTICES. All notices shall be addressed as follows:

        IF TO LESSOR:                            IF TO LESSEE:

        Lighthouse Capital Partners II, L.P.     ChemConnect, Inc.
        100 Drake's Landing, Suite 260           44 Montgomery Street, Suite 250
        Greenbrae, CA 94904-3121                 San Francisco, CA 94104
        Attn.:  Contract Administration          Attn.:  Chief Financial Officer
        Phone: (415) 925-3370                    Phone: (415) 364.3300
        Fax: (415) 925-3387                      Fax: (415) 646-0010




                                       2
<PAGE>   14

        CONDITIONS TO THE FIRST EQUIPMENT SCHEDULE. On or prior to the date of
execution of the first Equipment Schedule under this Lease Line Schedule, Lessor
shall have received in form and substance satisfactory to Lessor, each of the
following:

        1.      A Warrant substantially in the form of EXHIBIT H to the Master
                Lease.

        2.      Copies, certified by the Secretary or Assistant Secretary or
                Chief Financial Officer of Lessee, of: (i) the Articles of
                Incorporation and By-Laws of Lessee (as amended to the date of
                the Lease) and (ii) the resolutions adopted by Lessee's board of
                directors authorizing the execution and delivery of this Lease,
                the Lease Line Schedule, the Equipment Schedules, the Warrant
                and the other documents referred in this Lease Line Schedule and
                the performance by Lessee of its obligations in such documents.

        3.      A Good Standing Certificate (including franchise tax status)
                with respect to Lessee from Lessee's state of incorporation,
                dated a date reasonably close to the date of acceptance of the
                Lease by Lessor.

        4.      A Software Rider substantially in the form of ANNEX B to this
                Lease Line Schedule.

        5.      Evidence of the insurance coverage required by SECTION 8 of the
                Master Lease.

        6.      All necessary consents of shareholders and other third parties
                with respect to the subject matter of the Master Lease, the
                Lease Line Schedule, the Equipment Schedules and the Warrant.


        CONDITIONS TO ALL FUNDINGS UNDER ALL EQUIPMENT SCHEDULES. On or prior to
each funding under each Equipment Schedule under this Lease Line Schedule, each
of the following conditions shall have been satisfied:

        1.      No Event of Default or event which, with notice or lapse of time
                or both, would become an Event of Default, has occurred and is
                continuing.

        2.      Lessor shall have received a Software Licenses Assignment
                Agreement in substantially the form of ANNEX B-1 to this Lease
                Line Schedule with respect to each Vendor of software to be
                financed under this Lease Line Schedule.

        3.      Lessor shall have received all necessary or desirable estoppel
                certificates and UCC filings, releases or terminations.

        4.      Lessor shall have used its best efforts to obtain a landlord
                waiver and consent in substantially the form of EXHIBIT E to the
                Master Lease with respect to each equipment location.

        5.      There shall not have occurred (i) any material adverse change to
                the general affairs, management, results of operations,
                condition (financial or otherwise) or prospects of Lessee,
                whether or not arising from transactions in the ordinary course
                of business, or (ii) any material adverse deviation by Lessee
                from the business plan of Lessee presented to and not
                disapproved by Lessor, since the date of the Master Lease.

        6.      Lessee shall have delivered to Lessor an Equipment Schedule
                covering the appropriate funding period.

        7.      Lessee shall have delivered to Lessor (i) in the case of a
                sale-leaseback, original vendor invoices, copies of canceled
                checks or other proof of payment, a Bill of Sale, a Delivery and
                Acceptance Certificate, and any UCC filings or other notices
                deemed necessary or desirable in connection with the
                sale-leaseback or (ii) at Lessor's request, in the case of a
                purchase of new equipment in excess of $50,000 from an equipment
                vendor, a Purchase Order and Invoice Assignment and a Delivery
                and Acceptance Certificate.

        8.      Payment of the Advance Rent.




                                       3.
<PAGE>   15


        9.      All terms and conditions in the Equipment Schedule shall have
                been satisfied by the Acceptance Date for the Equipment under
                such Equipment Schedule.

               All other documents as Lessor shall have reasonably requested.



LESSEE:                                    LESSOR:



CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By:     EXHIBIT ONLY                       By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.P.,
                                               its general partner
Name:  Phil J. Ringo
       -----------------------------
                                               By: LIGHTHOUSE CAPITAL
Title: President and COO                           PARTNERS, INC.,
       -----------------------------               its general partner


                                           By:
                                              ---------------------------------

                                           Name: Thomas Conneely
                                                 ------------------------------

                                           Title: Vice President, Operations
                                                  -----------------------------




ANNEX A     -   Stipulated Loss Value Table
ANNEX B     -   Software Rider
ANNEX B-1   -   Software License Assignment Agreement




                                       4.
<PAGE>   16


                                     ANNEX A

                           STIPULATED LOSS VALUE TABLE
                                       TO
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease"), by
and between LIGHTHOUSE CAPITAL PARTNERS II, L.P., a Delaware limited partnership
     ("Lessor"), and CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

In the case of an Event of Loss, the Stipulated Loss Value for each item of
leased Equipment is the Lessor's Cost for the item multiplied by Stipulated Loss
Value Percentage for the Rent Payment Number following the month of the Event of
Loss.


<TABLE>
<CAPTION>
                                   Stipulated                                                  Stipulated
        Rent                         Loss                       Rent                              Loss
       Payment                       Value                     Payment                            Value
        Number                     Percentage                   Number                         Percentage
        ------                     ----------                   ------                         ----------
<S>                                <C>                         <C>                               <C>
          1                         111.88%                      19                               69.19%
          2                         109.78%                      20                               66.76%
          3                         106.95%                      21                               64.31%
          4                         104.54%                      22                               61.85%
          5                         102.11%                      23                               59.36%
          6                          98.78%                      24                               56.86%
          7                          96.64%                      25                               54.33%
          8                          94.47%                      26                               51.79%
          9                          92.28%                      27                               49.22%
         10                          90.07%                      28                               46.63%
         11                          87.84%                      29                               44.03%
         12                          85.59%                      30                               41.40%
         13                          83.31%                      31                               38.74%
         14                          81.09%                      32                               35.07%
         15                          78.69%                      33                               31.64%
         16                          76.35%                      34                               27.76%
         17                          73.99%                      35                               23.88%
         18                          71.60%                      36 and thereafter                20.00%
</TABLE>




Lessee: _______________                           Lessor:  _______________





                                      16.
<PAGE>   17

                                     ANNEX B

                                 SOFTWARE RIDER



        THIS SOFTWARE RIDER (this "Rider") is made a part of Lease Line Schedule
No. 01 (the ("Lease Line Schedule") dated May 5, 1999, by and between LIGHTHOUSE
CAPITAL PARTNERS II, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee").

All capitalized terms used and not otherwise defined herein are defined in the
Lease Line Schedule.

        In the event any computer software (as described in any applicable
Equipment Schedule and collectively with all manuals, updates, revisions,
program and data files, and documentation relating thereto or used or usable in
connection therewith, the "Software"), is purchased or licensed pursuant to the
Lease Line Schedule, then, in addition to all other terms and conditions of the
Master Lease and the Lease Line Schedule, all of which are incorporated herein
by this reference:

        1. SOFTWARE AS GENERAL INTANGIBLES. All Software shall be "Equipment" as
defined under the Lease Line Schedule. Lessee hereby grants to Lessor as
collateral security for Lessee's payment and performance of all Lessee's
obligations of payment and performance under this Rider, the Lease Line
Schedule, the Master Lease, and every other present or future Equipment Schedule
or other agreement between Lessee and Lessor, a security interest in all of its
right, title and interest in and to the Software, including without limitation
general intangibles, licenses, and intellectual property rights with respect
thereto, but excluding all licenses and other agreements that by law or by the
terms thereof may not be assigned by Lessee or may only be assigned by Lessee
with the consent of the other party to such license or other agreement, and all
substitutions, modifications, replacements, additions, accessions, proceeds, and
products of, to, or for any of the foregoing.

        2. EXCLUSION OF WARRANTIES. Without limiting the generality of all
exclusions of warranty set forth in the Lease Line Schedule and Master Lease,
Lessor makes no and specifically excludes any representation or warranty
relating to any Software, including without limitation any warranty of title,
validity or enforceability of license, noninfringement, availability or quality
of vendor support, or fitness for any particular purpose.

        3. LICENSE ASSIGNMENT AGREEMENT. Lessee will use its best efforts to
obtain a License Assignment Agreement in form and substance satisfactory to
Lessor and as set forth on EXHIBIT 1 hereto (the "Software License Assignment
Agreement")prior to the advance by Lessor of any funds to any party with respect
to the Software. Breach by Lessee of any term or condition of any license
agreement governing the right to use any Software shall be an Event of Default
under SECTION 16(ii) of the Master Lease if such breach is likely to have a
material adverse effect on the Equipment or Lessor's rights under the Lease Line
Schedule, Master Lease or any other documents relating to the lease of the
Equipment to Lessee.

        4. APPLICABILITY OF LEASE. The Master Lease, Lease Line Schedule,
Equipment Schedule, Software License Assignment Agreement, and this Rider, and
all documents entered into in connection therewith, govern Lessee's obligations
of payment and performance to Lessor with respect to the Software, whether or
not the Software represents goods capable of being leased pursuant to the UCC.

        5. LICENSE PERFORMANCE. Lessee agrees that in addition to Lessor's
remedies following an Event of Default, Lessor may upon notice to Lessee
requiring the same cause Lessee to cease all use of the Software and to assemble
and deliver to Lessor the same in electronic or other form. Lessee shall remit
to Lessor upon demand any amounts due and payable with respect to the licensing
of any Software or the assignment thereof. Lessee agrees that monetary damages
are not a sufficient remedy and will not adequately compensate Lessor for
Lessee's breach of this Section, and that Lessor shall be entitled to seek
specific performance or other injunctive or equitable relief.





                                      17.
<PAGE>   18


        6. INTEGRATION. This Rider represents the entirety of the understanding
between the parties with respect to its subject matter, and may only be modified
by a written instrument signed by the party to be charged. All rights and
remedies of Lessor herein are in addition to, and not in limitation of, the
rights and remedies of Lessor under the Lease.


LESSEE:                                   LESSOR:


CHEMCONNECT, INC.                         LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By:   EXHIBIT ONLY                        By: LIGHTHOUSE MANAGEMENT
   ---------------------------------          PARTNERS II, L.P.,
                                              its general partner
Name: Phil J. Ringo
      ------------------------------      By: LIGHTHOUSE CAPITAL PARTNERS, INC.,
Title: President and COO                      its general partner
       -----------------------------

                                          By:
                                              ---------------------------------

                                          Name: Thomas Conneely
                                                -------------------------------

                                          Title: Vice President, Operations
                                                 ------------------------------




                                      18.
<PAGE>   19


                                    ANNEX B-1
                                    EXHIBIT 1
                      SOFTWARE LICENSE ASSIGNMENT AGREEMENT



        This SOFTWARE LICENSE ASSIGNMENT AGREEMENT (this "Agreement") is entered
into May 5, 1999, by and between ______________________ ("Vendor"), LIGHTHOUSE
CAPITAL PARTNERS II, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee"), with respect to certain
items of computer software purchased or licensed from Vendor as more
specifically described in attachments hereto (the "Software") in connection with
that certain Equipment Schedule No. 01 between Lessee and Lessor (collectively
with all documents entered into in connection therewith, the "Lease") dated May
5, 1999.

        1. ACKNOWLEDGMENT OF LICENSE. The parties acknowledge that the right to
use the Software is being acquired pursuant to a software license agreement (the
"License") between Vendor and Lessee, and agree as follows:

           (a) Lessee reaffirms all of its rights and obligations under the
License and under the Lease. Lessor is not a party to the License, but is an
express third party beneficiary thereof.

           (b) Lessee assigns to Lessor all of its rights and benefits, but
Lessee retains all the obligations and burdens, under the License. Vendor
consents to such assignment.

           (c) Lessor sublicenses back to Lessee, expiring once there has been
an Event of Default under the Lease, the rights and benefits under the License.

        2. ASSIGNMENT. Lessor may upon notice to Vendor succeed to all of
Lessee's right, title and interest in and to the License, and may sell or assign
the same to any person, without the imposition of any transfer fee payable to
Vendor, effective upon such person's execution of the License, who shall upon
such execution succeed to the obligations and burdens under such license.

        3. NO COMMITMENT. This is not a commitment by Lessor to purchase or
finance any other items of software or hardware other than the Software.

        4. INTEGRATION. This Agreement represents the entirety of the
understanding between the parties with respect to its subject matter, and may
only be modified by a written instrument signed by the party to be charged.


VENDOR                                     LIGHTHOUSE CAPITAL PARTNERS II, L.P.



By:                                        By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.P.,
                                               its general partner

By:
   ---------------------------------           By: LIGHTHOUSE CAPITAL
                                                   PARTNERS, INC.,
Title:                                             its general partner
      ------------------------------


CHEMCONNECT, INC.                              By:
                                                  -----------------------------

By: EXHIBIT ONLY                               Name: Thomas Conneely
    --------------------------------                 --------------------------

Name: Phil J. Ringo                            Title: Vice President, Operations
      ------------------------------                  -------------------------

Title: President and COO
       -----------------------------




                                      19.
<PAGE>   20

                                    EXHIBIT B



     EQUIPMENT SCHEDULE NO. 01, dated May 5, 1999 ("Equipment Schedule") to
    LEASE LINE SCHEDULE NO. 01, dated May 5, 1999 ("Lease Line Schedule"), to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease"),
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
             CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)



Total Lessor's Cost:     The total Lessor's Cost under this Equipment Schedule
                         shall be an amount equal to the sum of the Lessor's
                         Cost under each Delivery and Acceptance Certificate
                         executed by Lessee between the date of this Equipment
                         Schedule and ten days prior to the Commencement Date,
                         and which refers to this Equipment Schedule.

Lease Term:              36 Months

Commencement Date:       June 1, 1999

Interim Rent:            On or about the Commencement Date, Lessor shall send
                         Lessee a "Summary of Equipment Schedule" in the form of
                         ANNEX A hereto, specifying, among other things, the
                         applicable Interim Rent; provided, however, that any
                         failure by Lessor to send Lessee a Summary of Equipment
                         Schedule shall not relieve Lessee of its obligation to
                         pay rent hereunder.

Rental Factor:           The Rental Factor shall be set forth in the Summary of
                         Equipment Schedule.

Rental Payments:         The amount of the monthly Rental Payments, calculated
                         in accordance with the Lease Line Schedule and payable
                         monthly in advance, shall be set forth in the Summary
                         of Equipment Schedule. Payments shall be made to
                         Lessor's address set forth in the Lease Line Schedule.

Rental Payment Dates:    First day of each calendar month.

Equipment Description:   The Equipment shall be described in each Delivery and
                         Acceptance Certificate executed by Lessee between the
                         date of this Equipment Schedule and the Commencement
                         Date, and which refers to this Equipment Schedule.
                         Delivery and Acceptance Certificates under this
                         Equipment Schedule must be received by Lessor no later
                         than ten business days prior to the Commencement Date.

Equipment Location:      44 Montgomery Street, Suite 250, San Francisco,
                         California 94104

Terms and Conditions:    The terms and conditions of the above-referenced Master
                         Lease and Lease Line Schedule are incorporated herein.
                         In addition, the following attachments apply to this
                         Equipment Schedule only: None.




                                       1.
<PAGE>   21


No Default:              No Event of Default or event which, with notice or
                         lapse of time or both, would become an Event of
                         Default, has occurred and is continuing.




LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By: EXHIBIT ONLY                           By: LIGHTHOUSE MANAGEMENT
    --------------------------------           PARTNERS II, L.P.,
                                               its general partner
Name: Phil J. Ringo
      ------------------------------       By: LIGHTHOUSE CAPITAL
                                               its general partner
Title: President and COO
       -----------------------------


                                               By:
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------





                                       2.

<PAGE>   22


                                     ANNEX A

                     SUMMARY OF EQUIPMENT SCHEDULE NO. 01 to
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
           MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999
                         ("Master Lease") by and between
              LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
              CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)



Total Lessor's Cost:                           $__________

Total Interim Rent:                            $__________

Rental Factor:                                 2.98%

Rental Payments:                               36 payments of $__________
                                               each, payable monthly in advance


Amount of Advance Rent applied to this
Equipment Schedule:                            $__________




                                           LIGHTHOUSE CAPITAL PARTNERS II, L.P.

                                           By: LIGHTHOUSE MANAGEMENT
                                               PARTNERS II, L.P.,
                                               its general partner



                                               By: LIGHTHOUSE CAPITAL
                                                   PARTNERS, INC.,
                                                   its general partner

                                               By: EXHIBIT ONLY
                                                   ----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------



                                       3.

<PAGE>   23


                                    EXHIBIT C

                       DELIVERY AND ACCEPTANCE CERTIFICATE
                                      UNDER
                EQUIPMENT SCHEDULE NO. 01, dated May 5, 1999, to
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
           MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999
                                 by and between
     LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and CHEMCONNECT, INC.,
                       a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)


         Installation Address:             44 Montgomery Street, Suite 250,
                                           San Francisco, CA 94104

         Lessor's Cost:                    $__________

         Commencement Date:                June 1, 1999

         Equipment Description:


<TABLE>
<CAPTION>
      Qty               Model & Description        Original Unit Purchase Price           Lessor's Cost
      ---               -------------------        ----------------------------           -------------
<S>                        <C>                    <C>                                     <C>
                            SEE ANNEX A
</TABLE>


        Lessee acknowledges receipt and acceptance of the Equipment listed in
ANNEX A and agrees the Equipment has been delivered and is ready for use under
the terms of the above-referenced Master Equipment Lease Agreement, Lease Line
Schedule, and Equipment Schedule, the terms and conditions of which are
incorporated herein, including, without limitation, the obligation to pay
Interim Rent and to make Rental Payments.

Acceptance Date: __________, 1999


LESSEE:


CHEMCONNECT, INC.


By: EXHIBIT ONLY
    --------------------------------

Name: Phil J. Ringo
      ------------------------------

Title: President and COO
       -----------------------------

ANNEX A




                                       1.

<PAGE>   24


                                     ANNEX A

                              EQUIPMENT DESCRIPTION



<TABLE>
<CAPTION>
      Qty               Model & Description        Original Unit Purchase Price           Lessor's Cost
      ---               -------------------        ----------------------------           -------------
<S>                        <C>                    <C>                                     <C>
                            SEE ANNEX A
</TABLE>









                                       2.

<PAGE>   25

                                    ANNEX B-1

                                  BILL OF SALE


        For and in consideration of the sum of One Dollar ($1.00) and other
valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, CHEMCONNECT, INC. (herein "Seller"), does hereby sell, grant,
transfer and deliver all right, title and interest in and to the equipment
further described on ANNEX A hereto (herein the "Equipment"), together with all
warranties, guarantees or other similar rights with respect to the Equipment
("Equipment Warranties") unto LIGHTHOUSE CAPITAL PARTNERS II, L.P. (herein
"Purchaser") and to its successors and assigns to have and to hold said
Equipment and the Equipment Warranties forever. Except for the Equipment
Warranties, the Equipment is sold "as is" and "where is" and the description of
the Equipment is for the sole purpose of identifying it and is not part of the
basis of the bargain.

        Seller represents and warrants that it holds all right, title and
interest in and to the Equipment being transferred free and clear of all liens
and encumbrances of any kind and Seller does for itself, its successors and
assigns covenant and agree with Purchaser, its successors and assigns, to
warrant and defend the sale of the Equipment and the transfer of the Equipment
Warranties unto Purchaser, its successors and assigns against all and every
person and persons whomsoever claiming or laying claim to the same, except for
any defects in title or liens or encumbrances in or to the Equipment arising
solely by reason of Purchaser's own acts.

        THE WARRANTY SET FORTH IN THE FOREGOING PARAGRAPH AND THE EQUIPMENT
WARRANTIES ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES OF SELLER, WHETHER
WRITTEN, ORAL OR IMPLIED, AND SELLER SHALL NOT, BY VIRTUE OF HAVING SOLD THE
EQUIPMENT HEREWITH, BE DEEMED TO HAVE MADE ANY REPRESENTATION OF WARRANTY AS TO
THE MERCHANTABILITY, FITNESS, DESIGN OR CONDITION OF, OR AS TO THE QUALITY OF
THE MATERIAL OR WORKMANSHIP IN, THE EQUIPMENT.

        IN WITNESS WHEREOF, we have set our hand and seal this _________ day of
May, 1999.




LESSEE:


CHEMCONNECT, INC.

By: EXHIBIT ONLY
   ---------------------------------

Name: Phil J. Ringo
      ------------------------------

Title: President and COO
       -----------------------------





                                      1
<PAGE>   26

                                    ANNEX B-2


        THIS PURCHASE ORDER ASSIGNMENT, dated as of _____, 199____ (this
"Assignment"), between CHEMCONNECT, INC. ("Assignor") and LIGHTHOUSE CAPITAL
PARTNERS II, L.P. ("Assignee").


                              W I T N E S S E T H :


        WHEREAS, Assignor has submitted its Purchase Orders and Invoices listed
in SCHEDULE 1 hereto (collectively, the "Purchase Orders"), to
___________________ (the "Vendor") concerning certain units of equipment (the
"Units") listed in SCHEDULE 1 hereto to be subject to a Master Equipment Lease
Agreement No. 219, dated as of May 5, 1999 (the "Master Lease"), between
Assignor and Assignee (all terms used but not otherwise defined herein shall
have the meaning given to them in the Master Lease):

        NOW, THEREFORE, in consideration of the premises and the mutual
covenants herein contained, the parties hereto agree as follows:

        1. Assignor does hereby sell, assign, transfer and set over unto
Assignee, all of the Assignor's rights to and interests in the Purchase Orders
as and to the extent that the same relates to the Units. The assignment herein
shall include, without limitation, the right of Assignee to purchase the Units
pursuant to the Purchase Orders and to take title to the Units, all claims for
damages in respect of the Units arising as a result of any default by Vendor
under the Purchase Orders, together with any and all rights of Assignor to
compel performance of the terms of the Purchase Orders in respect of the Units.

        2. The exercise by Assignee of any of the rights assigned hereunder
shall not release Assignor from any of its duties or obligations to Vendor under
the Purchase Orders except to the extent that such exercise by Assignee shall
constitute performance of such duties and obligations.

        3. Upon satisfaction of the conditions set forth in the applicable Lease
Line Schedule to the Master Lease with respect to the Units, Assignee shall
purchase such Unit by paying or causing to be paid, by check mailed or delivered
to Vendor, on such date or thereafter as permitted by Vendor, an amount equal to
the purchase price of the Unit, as such amount may be adjusted in accordance
with the terms of the Purchase Orders and reflected on invoices prepared by
Vendor to Assignee on or before the date of delivery and acceptance of the Unit.

        4. Assignor agrees that it will, at any time and from time to time, upon
the written consent of Assignee, promptly and duly exercise and deliver any and
all such further instruments and documents and take such further action as
Assignee may reasonably request in order that Assignee may obtain the full
benefits of this Agreement and of the rights and powers herein granted.

        5. Assignor represents and warrants that the Purchase Orders are in full
force and effect and that Assignor is not in default under any of them. Assignor
further represents and warrants that Assignor has not assigned or pledged, and
so long as this Assignment shall remain in effect, will not assign or pledge,
the whole or any part of the rights hereby assigned or any of its rights with
respect to the Units under the Purchase Orders to anyone other than Assignee.





                                       1.
<PAGE>   27

        IN WITNESS WHEREOF, the parties hereto have caused this Purchase Order
Assignment to be duly executed as of the day and year first above written.



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By: EXHIBIT ONLY                           By: LIGHTHOUSE MANAGEMENT
   -----------------------------               PARTNERS II, L.P.,
                                               its general partner
Name: Phil J. Ringo
     ---------------------------               By: LIGHTHOUSE CAPITAL
Title: President and COO                           PARTNERS, INC.,
      --------------------------                   its general partner

                                               By:
                                                  -----------------------------
                                               Name: Thomas Conneely
                                                     --------------------------
                                               Title: Vice President, Operations
                                                      -------------------------


Acknowledged and Consented to this ____________ day of __________, 199___.


VENDOR:



By:
   ---------------------------------

Name:
     -------------------------------

Title:
      ------------------------------




                                       2.
<PAGE>   28

                                    EXHIBIT D


                               NOTICE OF ELECTION


                                      under


                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
           MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999
      ("Master Lease") by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P.
        ("Lessor") and CHEMCONNECT, a California corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

        1. Pursuant to SECTION 4(d) of the Master Lease, Lessee hereby elects
the Lease Termination Option indicated below for the above Lease Line Schedule.

                Option Election            (check one)

                Purchase                   ______________________
                Renew                      ______________________
                Return                     ______________________

        2. If the renewal option is selected, then Lessee and Lessor must agree
upon the rental period and rental amount. If Lessee and Lessor are unable to
agree upon the terms of renewal, then this Notice of Election shall be deemed
invalid and a new Notice of Election must be submitted by Lessee.


Dated: __________________


                                           CHEMCONNECT

                                           By: EXHIBIT ONLY
                                               --------------------------------

                                           Name: Phil J. Ringo
                                                 ------------------------------

                                           Title: President and COO
                                                  -----------------------------



<PAGE>   29

                                    EXHIBIT E



RECORDING REQUESTED BY
AND WHEN RECORDED RETURN TO:
Lighthouse Capital Partners II, L.P.
100 Drake's Landing Road, Suite 260
Greenbrae, CA  94904-3121
Attn.: Contract Administration


________________________________________________________________________________
                     CONSENT TO REMOVAL OF PERSONAL PROPERTY


KNOW ALL PERSONS BY THESE PRESENTS:

        (a) The undersigned has an interest as owner and landlord in that
certain real property (the "Real Property") in the County of Santa Clara, State
of California, described as: SEE EXHIBIT 1 ATTACHED HERETO FOR FULL LEGAL
DESCRIPTION, and commonly known as 44 Montgomery Street, Suite 250, San
Francisco, California 94104 (Parcel No. ).

        (b) CHEMCONNECT, INC., a Delaware corporation ("Lessee"), has entered
into or will enter into a Master Equipment Lease Agreement with LIGHTHOUSE
CAPITAL PARTNERS II, L.P. ("Lessor") (as amended and supplemented from time to
time, the "Lease Agreement").

        (c) Lessor, as a condition to entering into the Lease Agreement,
requires that the undersigned consent to the removal by Lessor of the equipment
and other assets covered by the Lease Agreement (hereinafter the "Equipment")
from the Real Property, no matter how it is affixed thereto, and to the other
matters set forth below.

NOW, THEREFORE, for good and sufficient consideration, receipt of which is
hereby acknowledged, the undersigned consents to the placing of the Equipment on
the Real Property, and agrees with Lessor as follows:

        1. The undersigned waives and releases each and every right which
undersigned now has, under the laws of the State of California or by virtue of
the lease for the Real Property now in effect, to levy or distrain upon for
rent, in arrears, in advance or both, or to claim or assert title to the
Equipment that is already on said Real Property, or may hereafter be delivered
or installed thereon.

        2. The Equipment shall be considered to be personal property and shall
not be considered part of the Real Property regardless of whether or by what
means it is or may become attached or affixed to the Real Property.

        3. The undersigned will permit Lessor, or its agent or representative,
to enter upon the Real Property for the purpose of exercising any right it may
have under the terms of the Lease Agreement or otherwise, including, without
limitation, the right to remove the Equipment; provided, however, that if
Lessor, in removing the Equipment damages any improvements of the undersigned on
the Real Property, Lessor will, at its expense, cause same to be repaired,
normal wear and tear excepted. The right of Lessor to enter the Real Property
shall not terminate until thirty (30) days after Lessor receives written notice
from the undersigned of the termination of the Lease.

        4. This agreement shall be binding upon the heirs, successors and
assigns of the undersigned and shall inure to the benefit of Lessor and its
successors and assigns.

IN WITNESS WHEREOF, the undersigned has executed this instrument this ____ day
of __________________, 1999.



LANDLORD                                   Notarial Acknowledgment required.

By: EXHIBIT ONLY
   ---------------------------------
Name:
     -------------------------------
Title:
      ------------------------------



                  ATTACH LEGAL DESCRIPTION OF THE REAL PROPERTY




<PAGE>   30

                                    EXHIBIT F


                  ACKNOWLEDGMENT FROM USER OF MOBILE EQUIPMENT

                                      UNDER

     EQUIPMENT SCHEDULE NO. 01, dated May 5, 1999 ("Equipment Schedule"), to
    LEASE LINE SCHEDULE NO. 01, dated May 5, 1999 ("Lease Line Schedule"), to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease")
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
             CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

        1. The undersigned acknowledges and agrees that:

           (a) the Equipment listed below is owned by Lessor and is subject to
the terms and conditions of the Master Lease, Lease Line Schedule and Equipment
Schedule; and

           (b) upon the occurrence and continuance of an Event of Default under
the Master Lease, Lessor may, among other things, take possession of the
Equipment and upon request the undersigned agrees to make such Equipment
available to Lessor.

        2. The undersigned's address is:


            ________________________
            ________________________
            ________________________
            Phone:__________________
            Fax:____________________


<TABLE>
    QTY                    MODEL & DESCRIPTION                     SERIAL NUMBER                       LCP ASSET TAG NUMBER
    ---                    -------------------                     -------------                       --------------------
<S>                       <C>                                     <C>                                  <C>
     1
</TABLE>

        IN WITNESS WHEREOF, the undersigned has executed this Acknowledgment as
of the date written below.


Dated: _______________, 1999

                                               MOBILE EQUIPMENT USER

                                               By: EXHIBIT ONLY
                                                   ----------------------------

                                               Name:
                                                     --------------------------

                                               Title:
                                                     --------------------------


<PAGE>   31

                                    EXHIBIT G


                               OPINION OF COUNSEL
                                CHEMCONNECT, INC.



This requirement has been waived for all funding under Lease Line Schedule No.
01 to Master Equipment Lease Agreement No. 219.










<PAGE>   32

                                    EXHIBIT H



THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "1933 ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT
BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE
REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER
EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS
AVAILABLE WITH RESPECT THERETO.


                        PREFERRED STOCK PURCHASE WARRANT


Warrant No. __________                                  Number of Shares: 21,539
                                                        Series B Preferred Stock


                                CHEMCONNECT, INC.

                           Void after April 30, 2006


        1. ISSUANCE. This Warrant is issued to LIGHTHOUSE CAPITAL PARTNERS II,
L.P. by CHEMCONNECT, INC., a Delaware corporation (hereinafter with its
successors called the "Company").

        2. PURCHASE PRICE; NUMBER OF SHARES. The registered holder of this
Warrant (the "Holder"), commencing on the date hereof, is entitled upon
surrender of this Warrant with the subscription form annexed hereto duly
executed, at the principal office of the Company, to purchase from the Company
the following securities (collectively, the "Shares") at a price per share of
$1.30 (the "Purchase Price"), 21,539 fully paid and nonassessable shares of
Series B Preferred Stock, $0.0001 par value, of the Company (the "Preferred
Stock"). Until such time as this Warrant is exercised in full or expires, the
Purchase Price and the securities issuable upon exercise of this Warrant are
subject to adjustment as hereinafter provided. The person or persons in whose
name or names any certificate representing shares of Preferred Stock is issued
hereunder shall be deemed to have become the holder of record of the shares
represented thereby as at the close of business on the date this Warrant is
exercised with respect to such shares, whether or not the transfer books of the
Company shall be closed.

        3. PAYMENT OF PURCHASE PRICE. The Purchase Price may be paid (i) in cash
or by check, (ii) by the surrender by the Holder to the Company of any
promissory notes or other obligations issued by the Company, with all such notes
and obligations so surrendered being credited against the Purchase Price in an
amount equal to the principal amount thereof plus accrued interest to the date
of surrender, or (iii) by any combination of the foregoing.

        4. NET ISSUE ELECTION. The Holder may elect to receive, without the
payment by the Holder of any additional consideration, shares of Preferred Stock
equal to the value of this Warrant or any portion hereof by the surrender of
this Warrant or such portion to the Company, with the net issue election notice
annexed hereto duly executed, at the principal office of the Company. Thereupon,
the Company shall issue to the Holder such number of fully paid and
nonassessable shares of Preferred Stock as is computed using the following
formula:

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

where: X = the number of shares of Preferred Stock to be issued to the Holder
           pursuant to this SECTION 4.

           Y = the number of shares of Preferred Stock covered by this Warrant
               in respect of which the net issue election is made pursuant to
               this SECTION 4.

           A = the Fair Market Value (defined below) of one share of Preferred
               Stock, as determined at the time the net issue election is made
               pursuant to this SECTION 4.





<PAGE>   33


           B = the Purchase Price in effect under this Warrant at the time the
               net issue election is made pursuant to this SECTION 4. "Fair
               Market Value" of a share of Preferred Stock (or Common Stock if
               the Preferred Stock has been automatically converted into Common
               Stock) as of a particular date (the "Determination Date") shall
               mean:

                (a) If the net issue election is made in connection with and
        contingent upon the closing of the sale of the Company's Common Stock to
        the public in a public offering pursuant to a Registration Statement
        under the Securities Act of 1933 ("1933 Act") (a "Public Offering"), and
        if the Company's Registration Statement relating to such Public Offering
        ("Registration Statement") has been declared effective by the Securities
        and Exchange Commission, then the initial "Price to Public" specified in
        the final prospectus with respect to such offering multiplied by the
        number of shares of Common Stock into which each share of Preferred
        Stock is then convertible.

                (b) If the net issue election is not made in connection with and
        contingent upon a Public Offering, then as follows:

                        (i) If traded on a securities exchange or the Nasdaq
                National Market, the fair market value of the Common Stock shall
                be deemed to be the average of the closing or last reported sale
                prices of the Common Stock on such exchange or market over the
                five day period ending five business days prior to the
                Determination Date, and the fair market value of the Preferred
                Stock shall be deemed to be such fair market value of the Common
                Stock multiplied by the number of shares of Common Stock into
                which each share of Preferred Stock is then convertible;

                        (ii) If otherwise traded in an over-the-counter market,
                the fair market value of the Common Stock shall be deemed to be
                the average of the closing ask prices of the Common Stock over
                the five day period ending five business days prior to the
                Determination Date, and the fair market value of the Preferred
                Stock shall be deemed to be such fair market value of the Common
                Stock multiplied by the number of shares of Common Stock into
                which each share of Preferred Stock is then convertible; and

                        (iii) If there is no public market for the Common Stock,
                then fair market value shall be determined in good faith by the
                Company's Board of Directors.

        5. PARTIAL EXERCISE. This Warrant may be exercised in part, and the
Holder shall be entitled to receive a new warrant, which shall be dated as of
the date of this Warrant, covering the number of shares in respect of which this
Warrant shall not have been exercised.

        6. FRACTIONAL SHARES. In no event shall any fractional share of
Preferred Stock be issued upon any exercise of this Warrant. If, upon exercise
of this Warrant in its entirety, the Holder would, except as provided in this
SECTION 6, be entitled to receive a fractional share of Preferred Stock, then
the Company shall pay in lieu thereof, the Fair Market Value of such fractional
share in cash.

        7. EXPIRATION DATE; AUTOMATIC EXERCISE. This Warrant shall expire at the
close of business on April 30, 2006, and shall be void thereafter.
Notwithstanding the foregoing, this Warrant shall automatically be deemed to be
exercised in full pursuant to the provisions of SECTION 4 hereof, without any
further action on behalf of the Holder, immediately prior to the time this
Warrant would otherwise expire pursuant to the preceding sentence.

        8. RESERVED SHARES; VALID ISSUANCE. The Company covenants that it will
at all times from and after the date hereof reserve and keep available such
number of its authorized shares of Preferred Stock and Common Stock, $0.0001 par
value, of the Company (the "Common Stock"), free from all preemptive or similar
rights therein, as will be sufficient to permit, respectively, the exercise of
this Warrant in full and the conversion into shares of Common Stock of all
shares of Preferred Stock receivable upon such exercise. The Company further
covenants that such shares as may be issued pursuant to such exercise and/or
conversion will, upon issuance, be duly




                                       2.
<PAGE>   34

        and validly issued, fully paid and nonassessable and free from all
taxes, liens and charges with respect to the issuance thereof.

        9. STOCK SPLITS AND DIVIDENDS. If after the date hereof the Company
shall subdivide the Preferred Stock, by split-up or otherwise, or combine the
Preferred Stock, or issue additional shares of Preferred Stock in payment of a
stock dividend on the Preferred Stock, the number of shares of Preferred Stock
issuable on the exercise of this Warrant shall forthwith be proportionately
increased in the case of a subdivision or stock dividend, or proportionately
decreased in the case of a combination, and the Purchase Price shall forthwith
be proportionately decreased in the case of a subdivision or stock dividend, or
proportionately increased in the case of a combination.

        10. NO STOCKHOLDER RIGHTS. Except as expressly provided in this Warrant,
prior to exercise of this Warrant, the Holder shall not be entitled to any
rights of a stockholder with respect to the Shares, including without limitation
the right to vote such Shares, receive dividends or other distributions thereon,
exercise preemptive rights or be notified of stockholder meetings, and such
Holder shall not be entitled to any notice or other communication concerning the
business or affairs of the Company, provided, however, that nothing in this
SECTION 10 shall limit the right of the Holder to be provided the notices
required under the Warrant.

        11. MERGERS AND RECLASSIFICATIONS. If after the date hereof the Company
shall enter into any Reorganization (as hereinafter defined), then, as a
condition of such Reorganization, lawful provisions shall be made, and duly
executed documents evidencing the same from the Company or its successor shall
be delivered to the Holder, so that the Holder shall thereafter have the right
to purchase, at a total price not to exceed that payable upon the exercise of
this Warrant in full, the kind and amount of shares of stock and other
securities and property receivable upon such Reorganization by a holder of the
number of shares of Preferred Stock which might have been purchased by the
Holder immediately prior to such Reorganization, and in any such case
appropriate provisions shall be made with respect to the rights and interest of
the Holder to the end that the provisions hereof (including without limitation,
provisions for the adjustment of the Purchase Price and the number of shares
issuable hereunder and the provisions relating to the net issue election) shall
thereafter be applicable in relation to any shares of stock or other securities
and property thereafter deliverable upon exercise hereof. For the purposes of
this SECTION 11, the term "Reorganization" shall mean and refer to (i) an
acquisition of the Company by another entity by means of a merger,
consolidation, or other transaction or series of related transactions resulting
in the exchange of the outstanding shares of the Company's capital stock such
that stockholders of the Company prior to such transaction own, directly or
indirectly, less than 50% of the voting power of the surviving entity, or (ii) a
sale or transfer of all or substantially all of the Company's asset to any other
person.

        12. CERTIFICATE OF ADJUSTMENT. Whenever the Purchase Price is adjusted,
as herein provided, the Company shall promptly deliver to the Holder a
certificate of the Company's chief financial officer setting forth the Purchase
Price after such adjustment and setting forth a brief statement of the facts
requiring such adjustment.

        13. NOTICES OF RECORD DATE, ETC. In the event of:

            (a) any taking by the Company of a record of the holders of any
class of securities for the purpose of determining the holders thereof who are
entitled to receive any dividend or other distribution, or any right to
subscribe for, purchase, sell or otherwise acquire or dispose of any shares of
stock of any class or any other securities or property, or to receive any other
right;

            (b) any reclassification of the capital stock of the Company,
capital reorganization of the Company, consolidation or merger involving the
Company, or sale or conveyance of all or substantially all of its assets; or

            (c) any voluntary or involuntary dissolution, liquidation or
winding-up of the Company;

then in each such event the Company will provide or cause to be provided to the
Holder a written notice thereof. Such notice shall be provided at least twenty
(20) business days prior to the date specified in such notice on which any such
action is to be taken.



                                       3.
<PAGE>   35

        14. REPRESENTATIONS, WARRANTIES AND COVENANTS. This Warrant is issued
and delivered by the Company and accepted by each Holder on the basis of the
following representations, warranties and covenants made by the Company:

            (a) The Company has all necessary authority to issue, execute and
deliver this Warrant and to perform its obligations hereunder. This Warrant has
been duly authorized issued, executed and delivered by the Company and is the
valid and binding obligation of the Company, enforceable in accordance with its
terms.

            (b) The shares of Preferred Stock issuable upon the exercise of this
Warrant have been duly authorized and reserved for issuance by the Company and,
when issued in accordance with the terms hereof, will be validly issued, fully
paid and nonassessable.

            (c) The issuance, execution and delivery of this Warrant do not, and
the issuance of the shares of Preferred Stock upon the exercise of this Warrant
in accordance with the terms hereof will not, (i) violate or contravene the
Certificate or by-laws, or to the Company's knowledge, any law, statute,
regulation, rule, judgment or order applicable to the Company, (ii) violate,
contravene or result in a breach or default under any contract, agreement or
instrument to which the Company is a party or by which the Company or any of its
assets are bound or (iii) require the consent or approval of or the filing of
any notice or registration with any person or entity.

            (d) As long as this Warrant is, or any shares of Preferred Stock
issued upon exercise of this Warrant or any shares of Common Stock issued upon
conversion of such shares of Preferred Stock are, issued and outstanding, the
Company will provide to the Holder the financial and other information described
in that certain Lease Line Schedule No. 01 to Master Equipment Lease Agreement
No. 219 between the Company and Lighthouse Capital Partners II, L.P. dated as
of May 5, 1999.

            (e) As of the date hereof, the authorized capital stock of the
Company consists of (i) 19,000,000 shares of Common Stock, none of which are
issued and outstanding and 21,539 shares are reserved for issuance upon the
exercise of this Warrant and the conversion of the Preferred Stock, (ii)
5,686,573 shares of Series A Preferred Stock, all of which are issued and
outstanding, and (iii) 4,130,000 shares of Series B Preferred Stock, of which
3,970,000 are issued and outstanding shares and 21,539 shares are reserved for
issuance upon exercise of this Warrant. Attached hereto as EXHIBIT C is a
capitalization table summarizing the capitalization of the Company, including,
without limitation, the current Conversion Price of the Series B Preferred
Stock.

        15. INVESTORS' RIGHTS AGREEMENT. The Company agrees that, upon the next
amendment of that certain Amended and Restated Investors' Rights Agreement by
and among the Company, the Investors and the Founders listed therein dated as of
December 17, 1998 (the "Investors' Rights Agreement"), it will use its best
efforts to effect such amendment so that the Holder shall be an Investor within
the meaning of such Investors' Rights Agreement.

        16. RIGHT OF FIRST REFUSAL. Subject to the terms and conditions
contained in this SECTION 16, the Company agrees that the holder of this Warrant
has the right of first refusal to purchase its pro rata portion of any New
Securities (as defined in SECTION 16(a) below) which the Company may, from time
to time, propose to sell and issue. A holder's pro rata portion for purposes of
this SECTION 16 is the ratio that (x) the sum of the number of shares of the
Company's Common Stock then issued or issuable to the holder (including upon
conversion of any Preferred Stock held by the holder and upon exercise of this
Warrant and conversion of the Shares issued thereupon) bears to (y) the sum of
the total number of shares of Company's Common Stock then outstanding, the
number of shares of the Company's Common Stock issuable upon conversion of the
Preferred Stock then outstanding, and the number of shares of the Company's
Common Stock issuable to the holder upon exercise of this Warrant and conversion
of the Shares issued thereupon.




                                       4

<PAGE>   36

            (a) DEFINITION OF NEW SECURITIES. Except as set forth below, "New
Securities" shall mean any shares of capital stock of the Company, including
Common Stock and Preferred Stock, whether now authorized or not, and rights,
options or warrants to purchase said shares of Common Stock or Preferred Stock,
and securities of any type whatsoever that are, or may become, convertible into
or exercisable for said shares of Common Stock or Preferred Stock.
Notwithstanding the foregoing, "New Securities" does not include: (i) Common
Stock issuable upon conversion of any Preferred Stock outstanding as of the
grant date; (ii) securities offered to the public generally pursuant to a
registration statement under the Securities Act; (iii) securities issued
pursuant to the acquisition of another corporation by the Company by merger,
purchase of substantially all of the assets or shares or other reorganization;
(iv) shares of the Company's Common Stock or related options convertible into or
exercisable for such Common Stock issued to employees, officers and directors
of, and consultants to, the Company, pursuant to any compensatory benefit plan;
(v) stock issued pursuant to any rights or agreements, including, without
limitation, convertible securities, options and warrants, provided that the
Company shall have complied with the right of first refusal established by this
SECTION 16 with respect to the initial sale or grant by the Company of such
rights or agreements; or (vi) stock issued in connection with any stock split,
reverse stock split, stock dividend, combination or recapitalization by the
Company.

            (b) NOTICE OF RIGHT. In the event the Company proposes to undertake
an issuance of New Securities, it shall give the holder written notice of its
intention, describing the type of New Securities and the price and terms upon
which the Company proposes to issue the same. The holder shall have fifteen (15)
days from the date of receipt of any such notice to agree to purchase shares of
such New Securities (up to the amount referred to in this SECTION 16), for the
price and upon the terms specified in the notice, by giving written notice to
the Company and stating therein the quantity of New Securities to be purchased.

            (c) EXERCISE OF RIGHT. If the holder exercises its right of first
refusal hereunder, the closing of the purchase of the New Securities with
respect to which such right has been exercised shall take place within ninety
(90) calendar days after the holder gives notice of such exercise, which period
of time shall be extended in order to comply with applicable laws and
regulations. Upon exercise of such right of first refusal, the Company and the
holder shall be legally obligated to consummate the purchase contemplated
thereby and shall use their best efforts to secure any approvals required in
connection therewith.

            (d) LAPSE AND REINSTATEMENT OF RIGHT. In the event the holder fails
to exercise the right of first refusal provided in this SECTION 16 within said
fifteen (15) day period, the Company shall have ninety (90) days thereafter to
sell or enter into an agreement (pursuant to which the sale of New Securities
covered thereby shall be closed, if at all, within sixty (60) days from the date
of said agreement) to sell the New Securities not elected to be purchased by the
holder at the price and upon the terms no more favorable to the purchasers of
such securities than specified in the Company's notice. In the event the Company
has not sold the New Securities or entered into an agreement to sell the New
Securities within said ninety (90) day period (or sold and issued New Securities
in accordance with the foregoing within sixty (60) days from the date of said
agreement), the Company shall not thereafter issue or sell any New Securities
without first offering such securities to the holder in the manner provided
above.

            (e) ASSIGNMENT. The right of the holder to purchase any part of the
New Securities may be assigned in whole or in part to any partner, subsidiary,
affiliate or shareholder of the holder.

            (f) TERMINATION OF RIGHT OF FIRST REFUSAL. The right of first
refusal granted under SECTION 16 shall terminate on and be of no further force
or effect upon the closing of a firmly underwritten public offering of the
securities of the Company.

        17. AMENDMENT. The terms of this Warrant may be amended, modified or
waived only with the written consent of the Holder and the Company.

        18. REPRESENTATIONS AND COVENANTS OF THE HOLDER. This Preferred Stock
Purchase Warrant has been entered into by the Company in reliance upon the
following representations and covenants of the Holder, which by its execution
hereof the Holder hereby confirms:




                                       5

<PAGE>   37

            (a) INVESTMENT PURPOSE. The right to acquire Preferred Stock
issuable upon exercise of the Holder's rights contained herein or Common Stock
issuable upon conversion thereof (the "Conversion Shares") will be acquired for
investment and not with a view to the sale or distribution of any part thereof,
and the Holder has no present intention of selling or engaging in any public
distribution of the same except pursuant to a registration or exemption. The
Holder further represents that such Holder does not 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 Preferred Stock or Conversion Shares.

            (b) ACCREDITED INVESTOR. Holder is an "accredited investor" within
the meaning of the Securities and Exchange Rule 501 of Regulation D, as
presently in effect.

            (c) PRIVATE ISSUE. The Holder understands (i) that the Preferred
Stock issuable upon exercise of the Holder's rights contained herein and the
Conversion Shares is not registered under the 1933 Act or qualified under
applicable state securities laws on the ground that the issuance contemplated by
this Warrant will be exempt from the registration and qualifications
requirements thereof, and (ii) that the Company's reliance on such exemption is
predicated on the representations set forth in this SECTION 18.

            (d) FINANCIAL RISK. The Holder is an investor in securities of
companies in the development stage and has such knowledge and experience in
financial and business matters as to be capable of evaluating the merits and
risks of its investment and has the ability to bear the economic risks of its
investment.

            (e) DISCLOSURE OF INFORMATION. The Holder believes it has received
all the information it considers necessary or appropriate for deciding whether
to purchase the Warrant and the Preferred Stock issuable upon exercise thereof.
Such Holder further represents that it has had the opportunity to ask questions
and receive answers from the Company regarding the terms and conditions of the
Preferred Stock and the business, properties, prospects and financial condition
of the Company.

        19. NOTICES, TRANSFERS, ETC.

            (a) Any notice or written communication required or permitted to be
given to the Holder may be given by certified mail or delivered to the Holder at
the address most recently provided by the Holder to the Company.

            (b) Subject to compliance with applicable federal and state
securities laws, this Warrant may be transferred by the Holder with respect to
any or all of the shares purchasable hereunder. Upon surrender of this Warrant
to the Company, together with the assignment notice annexed hereto duly
executed, for transfer of this Warrant as an entirety by the Holder, the Company
shall issue a new warrant of the same denomination to the assignee. Upon
surrender of this Warrant to the Company, together with the assignment hereof
properly endorsed, by the Holder for transfer with respect to a portion of the
shares of Preferred Stock purchasable hereunder, the Company shall issue a new
warrant to the assignee, in such denomination as shall be requested by the
Holder hereof, and shall issue to such Holder a new warrant covering the number
of shares in respect of which this Warrant shall not have been transferred.

            (c) In case this Warrant shall be mutilated, lost, stolen or
destroyed, the Company shall issue a new warrant of like tenor and denomination
and deliver the same (i) in exchange and substitution for and upon surrender and
cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost,
stolen or destroyed, upon receipt of an affidavit of the Holder or other
evidence reasonably satisfactory to the Company of the loss, theft or
destruction of such Warrant

        20. NO IMPAIRMENT. The Company will not, by amendment of its Certificate
or through any reclassification, capital reorganization, consolidation, merger,
sale or conveyance of assets, dissolution, liquidation, issue or sale of
securities or any other voluntary action, avoid or seek to avoid the observance
of performance of any of the terms of this Warrant, but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the Holder.



                                       6.
<PAGE>   38

        21. GOVERNING LAW. The provisions and terms of this Warrant shall be
governed by and construed in accordance with the internal laws of the State of
California.

        22. SUCCESSORS AND ASSIGNS. This Warrant shall be binding upon the
Company's successors and assigns and shall inure to the benefit of the Holder's
successors, legal representatives and permitted assigns.

        23. BUSINESS DAYS. If the last or appointed day for the taking of any
action required or the expiration of any rights granted herein shall be a
Saturday or Sunday or a legal holiday in California, then such action may be
taken or right may be exercised on the next succeeding day which is not a
Saturday or Sunday or such a legal holiday.

        24. QUALIFYING PUBLIC OFFERING. If the Company shall effect a firm
commitment underwritten public offering of shares of Common Stock which results
in the conversion of the Preferred Stock into Common Stock pursuant to the
Certificate in effect immediately prior to such offering, then, effective upon
such conversion, this Warrant shall change from the right to purchase shares of
Preferred Stock to the right to purchase shares of Common Stock, and the Holder
shall thereupon have the right to purchase, at a total price equal to that
payable upon the exercise of this Warrant in full, the number of shares of
Common Stock which would have been receivable by the Holder upon the exercise of
this Warrant for shares of Preferred Stock immediately prior to such conversion
of such shares of Preferred Stock into shares of Common Stock, and in such event
appropriate provisions shall be made with respect to the rights and interest of
the Holder to the end that the provisions hereof (including, without limitation,
the provisions for the adjustment of the Purchase Price and of the number of
shares purchasable upon exercise of this Warrant and the provisions relating to
the net issue election) shall thereafter be applicable to any shares of Common
Stock deliverable upon the exercise hereof.

        25. VALUE. The Company and the Holder agree that the value of this
Warrant on the date of grant is $100.



Dated:  May ____, 1999                     CHEMCONNECT, INC.




                                           By: EXHIBIT ONLY
                                               --------------------------------

                                           Name: Phil J. Ringo
                                                 ------------------------------

                                           Title: President and COO
                                                  -----------------------------



               [CORPORATE SEAL]

Attest:



----------------------------





                                       7.
<PAGE>   39

                                  SUBSCRIPTION



To: ___________________________________________________     Date:______________


        The undersigned hereby subscribes for ____________ shares of Preferred
Stock covered by this Warrant. The certificate(s) for such shares shall be
issued in the name of the undersigned or as otherwise indicated below:


                                      Signature:
                                                -------------------------------

                                      Name for Registration:
                                                            -------------------

                                      Mailing Address:
                                                      -------------------------

                                      -----------------------------------------



                            NET ISSUE ELECTION NOTICE


To: ___________________________________________________     Date:______________

        The undersigned hereby elects under SECTION 4 to surrender the right to
purchase __________ shares of Preferred Stock pursuant to this Warrant. The
certificate(s) for such shares issuable upon such net issue election shall be
issued in the name of the undersigned or as otherwise indicated below:



                                      Signature:
                                                -------------------------------

                                      Name for Registration:
                                                            -------------------

                                      Mailing Address:
                                                      -------------------------

                                      -----------------------------------------





<PAGE>   40

                                   ASSIGNMENT



        For value received ______________________________ hereby sells, assigns
and transfers unto ____________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________



            [Please print or typewrite name and address of Assignee]
_______________________________________________________________________________
the within Warrant, and does hereby irrevocably constitute and appoint
____________________________________ its attorney to transfer the within Warrant
on the books of the within named Company with full power of substitution on the
premises.


Dated:__________________________


In the Presence of:


________________________________



<PAGE>   41

                                    EXHIBIT A

                      RESTATED CERTIFICATE OF INCORPORATION


                               See attached pages.





<PAGE>   42

                                    EXHIBIT B

                              CAPITALIZATION TABLE

                               See attached pages.





<PAGE>   43

                                    EXHIBIT I


                               ANCILLARY DOCUMENTS



Certificate of Secretary
UCC Financing Statement Attachment - Annex "A"
Insurance Request




<PAGE>   44

                                CHEMCONNECT, INC.

                            CERTIFICATE OF SECRETARY



        The undersigned, _______________, hereby certifies that:

        1.____________He/She is the duly elected and acting Secretary of
CHEMCONNECT, INC., a Delaware corporation (the "Company").

        2.____________That on the date hereof, each person listed below holds
the office in the Company indicated opposite his or her name and that the
signature appearing thereon is the genuine signature of each such person:


<TABLE>
<CAPTION>
        NAME                                OFFICE                                    SIGNATURE
        ----                                ------                                    ---------
<S>                                        <C>                                       <C>
        Phil J. Ringo                       President and COO                         _______________________
        _______________________             _______________________                   _______________________
        _______________________             _______________________                   _______________________
</TABLE>

        3.____________Attached hereto as EXHIBIT A is a true and correct copy of
the Certificate of Incorporation of the Company, as amended, as in effect as of
the date hereof.

        4.____________Attached hereto as EXHIBIT B is a true and correct copy of
the Bylaws of the Company, as amended, as in effect as of the date hereof.

        5.____________Attached hereto as EXHIBIT C is a copy of the resolutions
of the Board of Directors of the Company authorizing and approving the Company's
execution, delivery and performance of a lease line with Lighthouse Capital
Partners II, L.P.

        IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Secretary this ____ day of May 1999.



                                          CHEMCONNECT, INC.

                                          By:
                                              ---------------------------------

                                          Name:
                                                -------------------------------

                                          Title:
                                                -------------------------------



        I, the President and COO of the Company, do hereby certify that
_________________ is the duly qualified, elected and acting Secretary/Assistant
Secretary of the Company and that the above signature is his or her genuine
signature.

        IN WITNESS WHEREOF, the undersigned has executed and delivered this
Certificate of Secretary this ____ day of May 1999. --------------
CHEMCONNECT, INC.



                                           By: EXHIBIT ONLY
                                              ---------------------------------

                                           Name: Phil J. Ringo
                                                 ------------------------------

                                           Title: President and COO
                                                  -----------------------------


<PAGE>   45
                                    ANNEX "A"

                     UCC-1 FINANCING STATEMENT CONTINUATION




DEBTOR/LESSEE/TRANSFEROR:                  CHEMCONNECT, INC.

SECURED PARTY/LESSOR/TRANSFEREE:           LIGHTHOUSE CAPITAL PARTNERS II, L.P.


________________________________________________________________________________


COLLATERAL DESCRIPTION:

        All now owned or hereafter acquired equipment, software and other
personal property leased by Lessor to Lessee pursuant to any present or future
equipment lease, together with all substitutions, replacements, additions,
accessions, proceeds, and products of to or for any of the foregoing.

        Lessee has no right to sell or otherwise dispose of any of the
foregoing.

        As provided in Uniform Commercial Code Section 9408, the execution and
filing of this financing statement is not intended to imply and in no way
constitutes evidence that the described items of property are owned by the
Debtor/Lessee/Transferor. However, if notwithstanding the intent of the parties,
the Lease is held to create a secured financing or lease for security, the
Lessee shall be deemed to have granted to Lessor a security interest in the
above described equipment and other property.



                            -------------------         -------------------
                            Lessee Initials             Lessor Initials



<PAGE>   46

                              EVIDENCE OF INSURANCE



1.      CHEMCONNECT, INC.


RE:     Master Equipment Lease Agreement No. 219 ("Lease")


As required by SECTION 8 of the referenced Lease, please provide evidence of
insurance as outlined below:

~       "all risk" insurance against loss or damage to the equipment naming
        LIGHTHOUSE CAPITAL PARTNERS II, L.P. as LOSS PAYEE with respect to the
        equipment.

Minimum amount of "all risk" coverage: $700,000

-       commercial general liability insurance in an amount of at least
        $2,000,000 naming LIGHTHOUSE CAPITAL PARTNERS II, L.P. as an ADDITIONAL
        INSURED.

General Information:

CERTIFICATE HOLDER:

               Lighthouse Capital Partners II, L.P.
               100 Drake's Landing Road, Suite 260
               Greenbrae, CA 94904-3121
               Attn.:  Contract Administration

If you or your agent have any questions we can be reached at the above address
or by,

               phone:     415-925-3370

               fax:       415-925-3387

               e-mail:    leasing@lighthse.com


Please note that the above Certificate(s) of Insurance are required PRIOR to
funding under the Lease.



<PAGE>   47

     LEASE LINE SCHEDULE NO. 01, dated May 5, 1999 ("Lease Line Schedule"),
                                       to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease"),
                                 by and between
                LIGHTHOUSE CAPITAL PARTNERS II, L.P., a Delaware
                       limited partnership ("Lessor") and
             CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

IN CONSIDERATION of the mutual covenants contained herein, the parties agree as
follows:

        LEASE LINE. The total Lessor's Cost of all units of Equipment under all
Equipment Schedules pursuant to this Lease Line Schedule shall not exceed
$700,000.00 (the "Commitment"). "LESSOR'S COST" means, with respect to a unit of
Equipment, the total cost to Lessor of purchasing such unit, as indicated on the
applicable Equipment Schedule. Lessor's obligation to fund Equipment Schedules
under the Commitment shall terminate on December 31, 1999 (the "Commitment
Termination Date"). The minimum Lessor's Cost for each Delivery & Acceptance
Certificate shall be $10,000.00.

        RENTAL FACTOR. The Rental Factor for each Equipment Schedule will be
2.98% of scheduled Lessor's Cost per month, payable monthly in advance. The
Rental Payment under a particular Equipment Schedule shall be an amount equal to
the product of (a) the Rental Factor and (b) the aggregate Lessor's Cost of
Equipment subject to such Equipment Schedule.

        INTERIM RENT. The daily Interim Rent factor shall be equal to 0.0208%
for each item of Equipment (the "Interim Rate"). The daily Interim Rent payment
shall be an amount equal to the product of (a) 0.0208%, and (b) the Lessor's
Cost for each item of Equipment.

        ADVANCE RENT. On the Commencement Date set forth in each Equipment
Schedule to this Lease Line Schedule, Lessee shall pay to Lessor advance rent
equal to the product of (a) the Rental Factor and (b) the aggregate Lessor's
Cost of Equipment subject to such Equipment Schedule ("Advance Rent"), to be
applied toward the last Rental Payment due from Lessee to Lessor under each
Equipment Schedule.

        EXPENSES. Lessee agrees to reimburse Lessor for up to One Thousand
Dollars ($1,000.00) of expenses incurred in connection with the negotiation and
documentation of this transaction, promptly upon receipt of an invoice.

        ELIGIBLE EQUIPMENT. All equipment to be financed under an Equipment
Schedule must be Eligible Equipment. "Eligible Equipment" means the following
types of equipment to the extent acceptable to Lessor:

        Various new and used computers, peripherals, analytical and test
equipment, laboratory equipment and furniture, office furniture and equipment,
software in an amount not to exceed Two Hundred Ten Thousand Dollars ($210,000),
and other equipment as mutually agreed to by Lessee and Lessor, together with
all replacements, parts, cables, repairs, additions and accessories incorporated
therein or affixed thereto and all operating manuals and manufacturer's
instructions (collectively hereinafter called the "Equipment"). Such
replacements, parts, cables, repairs, additions and accessories shall (whether
or not purchased by Lessor) be considered part of the Equipment for all purposes
and, when installed in or attached to the Equipment (unless otherwise agreed),
be or become the property of the Lessor. Except as otherwise specifically
provided or the context so requires, the term "Equipment" includes operating
system or other bundled software which is delivered on or with the Equipment and
which constitutes an accession that could not be removed upon Lease Termination
without adversely affecting the functionality of Equipment in which it is
installed or is included on the Equipment Schedules. Equipment that is older
than ninety (90) days will be valued at its net book value, provided however,
that with respect to the first Equipment Schedule under this Lease Line,
Equipment that is older than one hundred twenty (120) days will be valued at its
net book value.

        COMMENCEMENT DATE. The "Commencement Date" for each Equipment Schedule
shall be the first day of the calendar month following the Acceptance Date for
the items of Equipment subject to such Equipment Schedule.


                                       1.
<PAGE>   48

        LEASE TERMINATION OPTIONS. Upon Lease Termination (as defined in the
Master Lease), Lessee will have, with respect to all but not less than all of
the Equipment governed by this Lease Line Schedule, the option to (a) purchase
the Equipment for the lesser of its then fair market value or twenty percent
(20%) of Lessor's Cost, (b) renew the Lease or (c) return the Equipment to
Lessor as provided in SECTION 6 of the Master Lease.

        ADVANCE NOTICE PERIOD. The "Advance Notice Period" shall be at least
ninety (90) days, but not more than 180 days, prior to Lease Termination (as
defined in the Master Lease) of Equipment Schedule No. 01 to this Lease Line
Schedule.

        AUTOMATIC EXTENSION PERIOD. The "Automatic Extension Period" shall equal
three (3) months and affects each Equipment Schedule under this Lease Line
Schedule.

        INSURANCE. The amount of commercial general liability insurance (other
than products liability coverage and completed operations insurance) required
under the Master Lease shall be at least $2,000,000 per occurrence. The amount
of the products liability and completed operations insurance under the Master
Lease shall be at least $2,000,000 per occurrence.

        FINANCIAL STATEMENTS. Lessee shall deliver to Lessor: (a) as soon as
available, but in any event within twenty (20) days after the end of each month,
a company prepared balance sheet, income statement and cash flow statement
covering Lessee's operations during such period, certified by an officer of
Lessee reasonably acceptable to Lessor; (b) as soon as available, but in any
event within ninety (90) days after the end of Lessee's fiscal year, audited
financial statements of Lessee prepared in accordance with generally accepted
accounting principles, consistently applied, together with an unqualified
opinion (other than a going concern qualification) on such financial statements
of an independent certified public accounting firm reasonably acceptable to
Lessor; (c) promptly upon becoming available, copies of all statements, reports,
budgets, sales projections, operating plans and notices sent or made available
generally by Lessee to its security holders; (d) immediately upon receipt of
notice thereof, a report of any material legal actions pending or threatened
against Lessee; and (e) such other financial information as Lessor may
reasonably request from time to time.

        MAINTENANCE SERVICE CONTRACTS. Lessee shall obtain and keep in effect at
all times during the Lease Term (and any renewal or extension thereof),
maintenance service contracts covering any Equipment with (i) a Lessor's Cost in
excess of $10,000 and/or (ii) Equipment for which maintenance service contracts
are customarily available with the Equipment supplier or with suppliers of
maintenance services approved by Lessor, such approval not to be unreasonably
withheld.

        INSTALLATION, HANDLING AND DELIVERY CHARGES. Any handling and delivery
charge to cover all Equipment transportation, rigging, drayage, packing,
installation and handling to and from vendor's plant and upon return to Lessor's
designated location shall be paid by Lessee.

        MISCELLANEOUS TAXES. Without limitation of the provisions of the Master
Lease, Lessee agrees to pay and to indemnify Lessor for any sales or use tax and
any property tax in connection with the sale, lease or use of the Equipment.

        LATE FEE. Lessee shall pay a late charge on any rent payments or other
sums due hereunder which are more than ten (10) days past due, in an amount
equal to 2% of the past due amount, payable on demand.

        DEFAULT RATE. The Default Rate of interest on late payments shall be
eighteen percent (18%) per annum.

        NOTICES. All notices shall be addressed as follows:

        IF TO LESSOR:                            IF TO LESSEE:

        Lighthouse Capital Partners II, L.P.     ChemConnect, Inc.
        100 Drake's Landing, Suite 260           44 Montgomery Street, Suite 250
        Greenbrae, CA 94904-3121                 San Francisco, CA 94104
        Attn.:  Contract Administration          Attn.:  Chief Financial Officer
        Phone: (415) 925-3370                    Phone: (415) 364.3300
        Fax: (415) 925-3387                      Fax: (415) 646-0010


                                       2
<PAGE>   49

        CONDITIONS TO THE FIRST EQUIPMENT SCHEDULE. On or prior to the date of
execution of the first Equipment Schedule under this Lease Line Schedule, Lessor
shall have received in form and substance satisfactory to Lessor, each of the
following:

        1.      A Warrant substantially in the form of EXHIBIT H to the Master
                Lease.

        2.      Copies, certified by the Secretary or Assistant Secretary or
                Chief Financial Officer of Lessee, of: (i) the Articles of
                Incorporation and By-Laws of Lessee (as amended to the date of
                the Lease) and (ii) the resolutions adopted by Lessee's board of
                directors authorizing the execution and delivery of this Lease,
                the Lease Line Schedule, the Equipment Schedules, the Warrant
                and the other documents referred in this Lease Line Schedule and
                the performance by Lessee of its obligations in such documents.

        3.      A Good Standing Certificate (including franchise tax status)
                with respect to Lessee from Lessee's state of incorporation,
                dated a date reasonably close to the date of acceptance of the
                Lease by Lessor.

        4.      A Software Rider substantially in the form of ANNEX B to this
                Lease Line Schedule.

        5.      Evidence of the insurance coverage required by SECTION 8 of the
                Master Lease.

        6.      All necessary consents of shareholders and other third parties
                with respect to the subject matter of the Master Lease, the
                Lease Line Schedule, the Equipment Schedules and the Warrant.


        CONDITIONS TO ALL FUNDINGS UNDER ALL EQUIPMENT SCHEDULES. On or prior to
each funding under each Equipment Schedule under this Lease Line Schedule, each
of the following conditions shall have been satisfied:

        1.      No Event of Default or event which, with notice or lapse of time
                or both, would become an Event of Default, has occurred and is
                continuing.

        2.      Lessor shall have received a Software Licenses Assignment
                Agreement in substantially the form of ANNEX B-1 to this Lease
                Line Schedule with respect to each Vendor of software to be
                financed under this Lease Line Schedule.

        3.      Lessor shall have received all necessary or desirable estoppel
                certificates and UCC filings, releases or terminations.

        4.      Lessor shall have used its best efforts to obtain a landlord
                waiver and consent in substantially the form of EXHIBIT E to the
                Master Lease with respect to each equipment location.

        5.      There shall not have occurred (i) any material adverse change to
                the general affairs, management, results of operations,
                condition (financial or otherwise) or prospects of Lessee,
                whether or not arising from transactions in the ordinary course
                of business, or (ii) any material adverse deviation by Lessee
                from the business plan of Lessee presented to and not
                disapproved by Lessor, since the date of the Master Lease.

        6.      Lessee shall have delivered to Lessor an Equipment Schedule
                covering the appropriate funding period.

        7.      Lessee shall have delivered to Lessor (i) in the case of a
                sale-leaseback, original vendor invoices, copies of canceled
                checks or other proof of payment, a Bill of Sale, a Delivery and
                Acceptance Certificate, and any UCC filings or other notices
                deemed necessary or desirable in connection with the
                sale-leaseback or (ii) at Lessor's request, in the case of a
                purchase of new equipment in excess of $50,000 from an equipment
                vendor, a Purchase Order and Invoice Assignment and a Delivery
                and Acceptance Certificate.

        8.      Payment of the Advance Rent.



                                       3
<PAGE>   50


        9.      All terms and conditions in the Equipment Schedule shall have
                been satisfied by the Acceptance Date for the Equipment under
                such Equipment Schedule.

        All other documents as Lessor shall have reasonably requested.



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By:  /s/ Philip J. Ringo                   By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.P.,
                                               its general partner
Name: Phil J. Ringo
      ------------------------------

Title: President and COO                   By: LIGHTHOUSE CAPITAL
       -----------------------------           PARTNERS, INC.,
                                               its general partner


                                               By: /s/ Thomas Conneely
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------




ANNEX A      -     Stipulated Loss Value Table
ANNEX B      -     Software Rider
ANNEX B-1    -     Software License Assignment Agreement



                                       4
<PAGE>   51

                                     ANNEX A

                           STIPULATED LOSS VALUE TABLE
                                       TO
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
      MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999
     ("Master Lease"), by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P.,
        a Delaware limited partnership ("Lessor"), and CHEMCONNECT, INC.,
                       a Delaware corporation ("Lessee").


(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)

In the case of an Event of Loss, the Stipulated Loss Value for each item of
leased Equipment is the Lessor's Cost for the item multiplied by Stipulated Loss
Value Percentage for the Rent Payment Number following the month of the Event of
Loss.



<TABLE>
<CAPTION>
                                 Stipulated                                                  Stipulated
         Rent                        Loss                      Rent                             Loss
        Payment                     Value                    Payment                            Value
        Number                   Percentage                   Number                         Percentage
        ------                   ----------                   ------                         ----------
<S>                               <C>                         <C>                              <C>
          1                        111.88%                      19                              69.19%
          2                        109.78%                      20                              66.76%
          3                        106.95%                      21                              64.31%
          4                        104.54%                      22                              61.85%
          5                        102.11%                      23                              59.36%
          6                         98.78%                      24                              56.86%
          7                         96.64%                      25                              54.33%
          8                         94.47%                      26                              51.79%
          9                         92.28%                      27                              49.22%
         10                         90.07%                      28                              46.63%
         11                         87.84%                      29                              44.03%
         12                         85.59%                      30                              41.40%
         13                         83.31%                      31                              38.74%
         14                         81.09%                      32                              35.07%
         15                         78.69%                      33                              31.64%
         16                         76.35%                      34                              27.76%
         17                         73.99%                      35                              23.88%
         18                         71.60%                      36 and thereafter               20.00%
</TABLE>


Lessee:   PJR                                     Lessor:     R
        ---------------                                    ---------------


<PAGE>   52

                                     ANNEX B

                                 SOFTWARE RIDER



        THIS SOFTWARE RIDER (this "Rider") is made a part of Lease Line Schedule
No. 01 (the ("Lease Line Schedule") dated May 5, 1999, by and between LIGHTHOUSE
CAPITAL PARTNERS II, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee").

All capitalized terms used and not otherwise defined herein are defined in the
Lease Line Schedule.

        In the event any computer software (as described in any applicable
Equipment Schedule and collectively with all manuals, updates, revisions,
program and data files, and documentation relating thereto or used or usable in
connection therewith, the "Software"), is purchased or licensed pursuant to the
Lease Line Schedule, then, in addition to all other terms and conditions of the
Master Lease and the Lease Line Schedule, all of which are incorporated herein
by this reference:

        1. SOFTWARE AS GENERAL INTANGIBLES. All Software shall be "Equipment" as
defined under the Lease Line Schedule. Lessee hereby grants to Lessor as
collateral security for Lessee's payment and performance of all Lessee's
obligations of payment and performance under this Rider, the Lease Line
Schedule, the Master Lease, and every other present or future Equipment Schedule
or other agreement between Lessee and Lessor, a security interest in all of its
right, title and interest in and to the Software, including without limitation
general intangibles, licenses, and intellectual property rights with respect
thereto, but excluding all licenses and other agreements that by law or by the
terms thereof may not be assigned by Lessee or may only be assigned by Lessee
with the consent of the other party to such license or other agreement, and all
substitutions, modifications, replacements, additions, accessions, proceeds, and
products of, to, or for any of the foregoing.

        2. EXCLUSION OF WARRANTIES. Without limiting the generality of all
exclusions of warranty set forth in the Lease Line Schedule and Master Lease,
Lessor makes no and specifically excludes any representation or warranty
relating to any Software, including without limitation any warranty of title,
validity or enforceability of license, noninfringement, availability or quality
of vendor support, or fitness for any particular purpose.

        3. LICENSE ASSIGNMENT AGREEMENT. Lessee will use its best efforts to
obtain a License Assignment Agreement in form and substance satisfactory to
Lessor and as set forth on EXHIBIT 1 hereto (the "Software License Assignment
Agreement")prior to the advance by Lessor of any funds to any party with respect
to the Software. Breach by Lessee of any term or condition of any license
agreement governing the right to use any Software shall be an Event of Default
under SECTION 16(ii) of the Master Lease if such breach is likely to have a
material adverse effect on the Equipment or Lessor's rights under the Lease Line
Schedule, Master Lease or any other documents relating to the lease of the
Equipment to Lessee.

        4. APPLICABILITY OF LEASE. The Master Lease, Lease Line Schedule,
Equipment Schedule, Software License Assignment Agreement, and this Rider, and
all documents entered into in connection therewith, govern Lessee's obligations
of payment and performance to Lessor with respect to the Software, whether or
not the Software represents goods capable of being leased pursuant to the UCC.

        5. LICENSE PERFORMANCE. Lessee agrees that in addition to Lessor's
remedies following an Event of Default, Lessor may upon notice to Lessee
requiring the same cause Lessee to cease all use of the Software and to assemble
and deliver to Lessor the same in electronic or other form. Lessee shall remit
to Lessor upon demand any amounts due and payable with respect to the licensing
of any Software or the assignment thereof. Lessee agrees that monetary damages
are not a sufficient remedy and will not adequately compensate Lessor for
Lessee's breach of this Section, and that Lessor shall be entitled to seek
specific performance or other injunctive or equitable relief.


<PAGE>   53

        6. INTEGRATION. This Rider represents the entirety of the understanding
between the parties with respect to its subject matter, and may only be modified
by a written instrument signed by the party to be charged. All rights and
remedies of Lessor herein are in addition to, and not in limitation of, the
rights and remedies of Lessor under the Lease.



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.


By: EXHIBIT ONLY                           By: LIGHTHOUSE MANAGEMENT
    ---------------------------------          PARTNERS II, L.L.C.,
Name: Phil J. Ringo                            its general partner
      ------------------------------

Title: President and COO                   By: LIGHTHOUSE CAPITAL PARTNERS,
       -----------------------------           INC., its general partner


                                               By:
                                                  -----------------------------
                                               Name: Thomas Conneely
                                                     --------------------------
                                               Title: Vice President, Operations
                                                      -------------------------



<PAGE>   54

                                    ANNEX B-1
                                    EXHIBIT 1
                      SOFTWARE LICENSE ASSIGNMENT AGREEMENT


        This SOFTWARE LICENSE ASSIGNMENT AGREEMENT (this "Agreement") is entered
into May 5, 1999, by and between ______________________ ("Vendor"), LIGHTHOUSE
CAPITAL PARTNERS II, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee"), with respect to certain
items of computer software purchased or licensed from Vendor as more
specifically described in attachments hereto (the "Software") in connection with
that certain Equipment Schedule No. 01 between Lessee and Lessor (collectively
with all documents entered into in connection therewith, the "Lease") dated May
5, 1999.

        1. ACKNOWLEDGMENT OF LICENSE. The parties acknowledge that the right to
use the Software is being acquired pursuant to a software license agreement (the
"License") between Vendor and Lessee, and agree as follows:

           (a) Lessee reaffirms all of its rights and obligations under the
License and under the Lease. Lessor is not a party to the License, but is an
express third party beneficiary thereof.

           (b) Lessee assigns to Lessor all of its rights and benefits, but
Lessee retains all the obligations and burdens, under the License. Vendor
consents to such assignment.

           (c) Lessor sublicenses back to Lessee, expiring once there has been
an Event of Default under the Lease, the rights and benefits under the License.

        2. ASSIGNMENT. Lessor may upon notice to Vendor succeed to all of
Lessee's right, title and interest in and to the License, and may sell or assign
the same to any person, without the imposition of any transfer fee payable to
Vendor, effective upon such person's execution of the License, who shall upon
such execution succeed to the obligations and burdens under such license.

        3. NO COMMITMENT. This is not a commitment by Lessor to purchase or
finance any other items of software or hardware other than the Software.

        4. INTEGRATION. This Agreement represents the entirety of the
understanding between the parties with respect to its subject matter, and may
only be modified by a written instrument signed by the party to be charged.


VENDOR                                     LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By:                                        By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.L.C.,
                                               its general partner

By:
   ---------------------------------           By: LIGHTHOUSE CAPITAL PARTNERS,
                                                   INC., its general partner
Title:
      ------------------------------           By:
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------
CHEMCONNECT, INC.
                                               Title: Vice President, Operations
                                                      --------------------------
By: EXHIBIT ONLY
    --------------------------------

Name: Phil J. Ringo
      ------------------------------

Title: President and COO
       -----------------------------



<PAGE>   55
                                 SOFTWARE RIDER


        THIS SOFTWARE RIDER (this "Rider") is made a part of Lease Line Schedule
No. 01 (the ("Lease Line Schedule") dated May 5, 1999, by and between LIGHTHOUSE
CAPITAL PARTNERS II, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee").

All capitalized terms used and not otherwise defined herein are defined in the
Lease Line Schedule.

        In the event any computer software (as described in any applicable
Equipment Schedule and collectively with all manuals, updates, revisions,
program and data files, and documentation relating thereto or used or usable in
connection therewith, the "Software"), is purchased or licensed pursuant to the
Lease Line Schedule, then, in addition to all other terms and conditions of the
Master Lease and the Lease Line Schedule, all of which are incorporated herein
by this reference:

        1. SOFTWARE AS GENERAL INTANGIBLES. All Software shall be "Equipment" as
defined under the Lease Line Schedule. Lessee hereby grants to Lessor as
collateral security for Lessee's payment and performance of all Lessee's
obligations of payment and performance under this Rider, the Lease Line
Schedule, the Master Lease, and every other present or future Equipment Schedule
or other agreement between Lessee and Lessor, a security interest in all of its
right, title and interest in and to the Software, including without limitation
general intangibles, licenses, and intellectual property rights with respect
thereto, but excluding all licenses and other agreements that by law or by the
terms thereof may not be assigned by Lessee or may only be assigned by Lessee
with the consent of the other party to such license or other agreement, and all
substitutions, modifications, replacements, additions, accessions, proceeds, and
products of, to, or for any of the foregoing.

        2. EXCLUSION OF WARRANTIES. Without limiting the generality of all
exclusions of warranty set forth in the Lease Line Schedule and Master Lease,
Lessor makes no and specifically excludes any representation or warranty
relating to any Software, including without limitation any warranty of title,
validity or enforceability of license, noninfringement, availability or quality
of vendor support, or fitness for any particular purpose.

        3. LICENSE ASSIGNMENT AGREEMENT. Lessee will use its best efforts to
obtain a License Assignment Agreement in form and substance satisfactory to
Lessor and as set forth on EXHIBIT 1 hereto (the "Software License Assignment
Agreement")prior to the advance by Lessor of any funds to any party with respect
to the Software. Breach by Lessee of any term or condition of any license
agreement governing the right to use any Software shall be an Event of Default
under SECTION 16(ii) of the Master Lease if such breach is likely to have a
material adverse effect on the Equipment or Lessor's rights under the Lease Line
Schedule, Master Lease or any other documents relating to the lease of the
Equipment to Lessee.

        4. APPLICABILITY OF LEASE. The Master Lease, Lease Line Schedule,
Equipment Schedule, Software License Assignment Agreement, and this Rider, and
all documents entered into in connection therewith, govern Lessee's obligations
of payment and performance to Lessor with respect to the Software, whether or
not the Software represents goods capable of being leased pursuant to the UCC.

        5. LICENSE PERFORMANCE. Lessee agrees that in addition to Lessor's
remedies following an Event of Default, Lessor may upon notice to Lessee
requiring the same cause Lessee to cease all use of the Software and to assemble
and deliver to Lessor the same in electronic or other form. Lessee shall remit
to Lessor upon demand any amounts due and payable with respect to the licensing
of any Software or the assignment thereof. Lessee agrees that monetary damages
are not a sufficient remedy and will not adequately compensate Lessor for
Lessee's breach of this Section, and that Lessor shall be entitled to seek
specific performance or other injunctive or equitable relief.



<PAGE>   56

        6. INTEGRATION. This Rider represents the entirety of the understanding
between the parties with respect to its subject matter, and may only be modified
by a written instrument signed by the party to be charged. All rights and
remedies of Lessor herein are in addition to, and not in limitation of, the
rights and remedies of Lessor under the Lease.



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.


By: /S/ PHILIP J. RINGO                    By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.L.C.,
                                               its general partner

Name: Phil J. Ringo                            By: LIGHTHOUSE MANAGEMENT
      ------------------------------           PARTNERS II, L.P.
                                                   its general partner

Title: President and COO
       -----------------------------

                                               By: /s/ THOMAS CONNEELY
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------


<PAGE>   57

                                    ANNEX B-1
                                    EXHIBIT 1
                      SOFTWARE LICENSE ASSIGNMENT AGREEMENT


        This SOFTWARE LICENSE ASSIGNMENT AGREEMENT (this "Agreement") is entered
into May 5, 1999, by and between ______________________ ("Vendor"), LIGHTHOUSE
CAPITAL PARTNERS III, L.P., a Delaware limited partnership ("Lessor") and
CHEMCONNECT, INC., a Delaware corporation ("Lessee"), with respect to certain
items of computer software purchased or licensed from Vendor as more
specifically described in attachments hereto (the "Software") in connection with
that certain Equipment Schedule No. 01 between Lessee and Lessor (collectively
with all documents entered into in connection therewith, the "Lease") dated May
5, 1999.

        1. ACKNOWLEDGMENT OF LICENSE. The parties acknowledge that the right to
use the Software is being acquired pursuant to a software license agreement (the
"License") between Vendor and Lessee, and agree as follows:

           (a) Lessee reaffirms all of its rights and obligations under the
License and under the Lease. Lessor is not a party to the License, but is an
express third party beneficiary thereof.

           (b) Lessee assigns to Lessor all of its rights and benefits, but
Lessee retains all the obligations and burdens, under the License. Vendor
consents to such assignment.

           (c) Lessor sublicenses back to Lessee, expiring once there has been
an Event of Default under the Lease, the rights and benefits under the License.

        2. ASSIGNMENT. Lessor may upon notice to Vendor succeed to all of
Lessee's right, title and interest in and to the License, and may sell or assign
the same to any person, without the imposition of any transfer fee payable to
Vendor, effective upon such person's execution of the License, who shall upon
such execution succeed to the obligations and burdens under such license.

        3. NO COMMITMENT. This is not a commitment by Lessor to purchase or
finance any other items of software or hardware other than the Software.

        4. INTEGRATION. This Agreement represents the entirety of the
understanding between the parties with respect to its subject matter, and may
only be modified by a written instrument signed by the party to be charged.



VENDOR                                     LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By:                                        By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.L.C.,
                                               its general partner

By:
   ---------------------------------           By: LIGHTHOUSE MANAGEMENT
                                                   PARTNERS II, L.P.,
                                                   its general partner
Title:
      ------------------------------           By:
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

CHEMCONNECT, INC.
                                               Title: Vice President, Operations
                                                      -------------------------


By: EXHIBIT ONLY
    --------------------------------

Name: Phil J. Ringo
      ------------------------------

Title: President and COO
       -----------------------------




<PAGE>   58

     EQUIPMENT SCHEDULE NO. 01, dated May 5, 1999 ("Equipment Schedule") to
    LEASE LINE SCHEDULE NO. 01, dated May 5, 1999 ("Lease Line Schedule"), to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease"),
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
             CHEMCONNECT, INC., a Delaware corporation ("Lessee").


(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)


Total Lessor's Cost:     The total Lessor's Cost under this Equipment Schedule
                         shall be an amount equal to the sum of the Lessor's
                         Cost under each Delivery and Acceptance Certificate
                         executed by Lessee between the date of this Equipment
                         Schedule and ten days prior to the Commencement Date,
                         and which refers to this Equipment Schedule.

Lease Term:              36 Months

Commencement Date:       June 1, 1999

Interim Rent:            On or about the Commencement Date, Lessor shall send
                         Lessee a "Summary of Equipment Schedule" in the form of
                         ANNEX A hereto, specifying, among other things, the
                         applicable Interim Rent; provided, however, that any
                         failure by Lessor to send Lessee a Summary of Equipment
                         Schedule shall not relieve Lessee of its obligation to
                         pay rent hereunder.

Rental Factor:           The Rental Factor shall be set forth in the Summary of
                         Equipment Schedule.

Rental Payments:         The amount of the monthly Rental Payments, calculated
                         in accordance with the Lease Line Schedule and payable
                         monthly in advance, shall be set forth in the Summary
                         of Equipment Schedule. Payments shall be made to
                         Lessor's address set forth in the Lease Line Schedule.

Rental Payment Dates:    First day of each calendar month.

Equipment Description:   The Equipment shall be described in each Delivery and
                         Acceptance Certificate executed by Lessee between the
                         date of this Equipment Schedule and the Commencement
                         Date, and which refers to this Equipment Schedule.
                         Delivery and Acceptance Certificates under this
                         Equipment Schedule must be received by Lessor no later
                         than ten business days prior to the Commencement Date.

Equipment Location:      44 Montgomery Street, Suite 250, San Francisco,
                         California 94104

Terms and Conditions:    The terms and conditions of the above-referenced Master
                         Lease and Lease Line Schedule are incorporated herein.
                         In addition, the following attachments apply to this
                         Equipment Schedule only: None.


<PAGE>   59

No Default:              No Event of Default or event which, with notice or
                         lapse of time or both, would become an Event of
                         Default, has occurred and is continuing.



LESSEE:                                    LESSOR:


CHEMCONNECT, INC.                          LIGHTHOUSE CAPITAL PARTNERS II, L.P.

By: /s/ PHILIP J. RINGO                    By: LIGHTHOUSE MANAGEMENT
   ---------------------------------           PARTNERS II, L.P.,
                                               its general partner

Name: Phil J. Ringo
                                           By: LIGHTHOUSE CAPITAL
Title: President and COO                       its general partner
       -----------------------------


                                               By: /s/ THOMAS CONNEELY
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------



<PAGE>   60

                                     ANNEX A

                     SUMMARY OF EQUIPMENT SCHEDULE NO. 01 to
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
 MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease")
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
              CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)


Total Lessor's Cost:                       $__________

Total Interim Rent:                        $__________

Rental Factor:                             2.98%

Rental Payments:                           36 payments of $
                                           each, payable monthly in advance

Amount of Advance Rent applied to this Equipment Schedule:   $__________




                                           LIGHTHOUSE CAPITAL PARTNERS II, L.P.

                                           By: LIGHTHOUSE MANAGEMENT
                                               PARTNERS II, L.P.,
                                               its general partner

                                           By: LIGHTHOUSE CAPITAL
                                               PARTNERS, INC.,
                                               its general partner


                                               By: EXHIBIT ONLY
                                                   ----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------




<PAGE>   61

                     SUMMARY OF EQUIPMENT SCHEDULE NO. 01 to
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease")
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
              CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)


Total Lessor's Cost:                       $629,913.14

Total Interim Rent:                        $0.00

Rental Factor:                             2.98%

Rental Payments:                           36 payments of $18,771.41
                                           each, payable monthly in advance

Amount of Advance Rent applied to this Equipment Schedule: $18,771.41




                                           LIGHTHOUSE CAPITAL PARTNERS II, L.P.

                                           By: LIGHTHOUSE MANAGEMENT
                                               PARTNERS II, L.P.,
                                               its general partner

                                               By: LIGHTHOUSE CAPITAL
                                                   PARTNERS, INC.,
                                                   its general partner

                                               By: /s/ THOMAS CONNEELY
                                                  -----------------------------
                                               Name: Thomas Conneely
                                                     --------------------------
                                               Title: Vice President, Operations
                                                      -------------------------


<PAGE>   62

                     SUMMARY OF EQUIPMENT SCHEDULE NO. 01 to
                LEASE LINE SCHEDULE NO. 01, dated May 5, 1999, to
  MASTER EQUIPMENT LEASE AGREEMENT NO. 219, dated May 5, 1999 ("Master Lease")
       by and between LIGHTHOUSE CAPITAL PARTNERS II, L.P. ("Lessor") and
              CHEMCONNECT, INC., a Delaware corporation ("Lessee").



(All capitalized terms not otherwise defined herein shall have the meanings
given to such terms in the Master Lease.)


Total Lessor's Cost                        $629,913.14

Total Interim Rent:                        $0.00

Rental Factor:                             2.98%

Rental Payments:                           36 payments of $18,771.41
                                           each, payable monthly in advance


Amount of Advance Rent applied to this Equipment Schedule:  $18,771.41




                                           LIGHTHOUSE CAPITAL PARTNERS II, L.P.

                                           By: LIGHTHOUSE MANAGEMENT
                                               PARTNERS II, L.P.,
                                               its general partner

                                               By: LIGHTHOUSE CAPITAL
                                                   PARTNERS, INC.,
                                                   its general partner

                                               By: /s/ THOMAS CONNEELY
                                                  -----------------------------

                                               Name: Thomas Conneely
                                                     --------------------------

                                               Title: Vice President, Operations
                                                      -------------------------




<PAGE>   63

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "1933 ACT"), OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY NOT
BE SOLD OR TRANSFERRED UNLESS SUCH SALE OR TRANSFER IS IN ACCORDANCE WITH THE
REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS OR SOME OTHER
EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND APPLICABLE LAWS IS
AVAILABLE WITH RESPECT THERETO.


                        PREFERRED STOCK PURCHASE WARRANT


Warrant No. __________                                 Number of Shares: 21,539
                                                       Series B Preferred Stock


                                CHEMCONNECT, INC.

                            Void after April 30, 2006


        1. ISSUANCE. This Warrant is issued to LIGHTHOUSE CAPITAL PARTNERS II,
L.P. by CHEMCONNECT, INC., a Delaware corporation (hereinafter with its
successors called the "Company").

        2. PURCHASE PRICE; NUMBER OF SHARES. The registered holder of this
Warrant (the "HOLDER"), commencing on the date hereof, is entitled upon
surrender of this Warrant with the subscription form annexed hereto duly
executed, at the principal office of the Company, to purchase from the Company
the following securities (collectively, the "SHARES") at a price per share of
$1.30 (the "PURCHASE PRICE"), 21,539 fully paid and nonassessable shares of
Series B Preferred Stock, $0.0001 par value, of the Company (the "PREFERRED
STOCK"). Until such time as this Warrant is exercised in full or expires, the
Purchase Price and the securities issuable upon exercise of this Warrant are
subject to adjustment as hereinafter provided. The person or persons in whose
name or names any certificate representing shares of Preferred Stock is issued
hereunder shall be deemed to have become the holder of record of the shares
represented thereby as at the close of business on the date this Warrant is
exercised with respect to such shares, whether or not the transfer books of the
Company shall be closed.

        3. PAYMENT OF PURCHASE PRICE. The Purchase Price may be paid (i) in cash
or by check, (ii) by the surrender by the Holder to the Company of any
promissory notes or other obligations issued by the Company, with all such notes
and obligations so surrendered being credited against the Purchase Price in an
amount equal to the principal amount thereof plus accrued interest to the date
of surrender, or (iii) by any combination of the foregoing.

        4. NET ISSUE ELECTION. The Holder may elect to receive, without the
payment by the Holder of any additional consideration, shares of Preferred Stock
equal to the value of this Warrant or any portion hereof by the surrender of
this Warrant or such portion to the Company, with the net issue election notice
annexed hereto duly executed, at the principal office of the Company. Thereupon,
the Company shall issue to the Holder such number of fully paid and
nonassessable shares of Preferred Stock as is computed using the following
formula:

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

where:      X = the number of shares of Preferred Stock to be issued to the
                Holder pursuant to this SECTION 4.

            Y = the number of shares of Preferred Stock covered by this Warrant
                in respect of which the net issue election is made pursuant to
                this SECTION 4.

            A = the Fair Market Value (defined below) of one share of Preferred
                Stock, as determined at the time the net issue election is made
                pursuant to this SECTION 4.


<PAGE>   64

            B = the Purchase Price in effect under this Warrant at the time
                the net issue election is made pursuant to this SECTION 4.

"FAIR MARKET VALUE" of a share of Preferred Stock (or Common Stock if the
Preferred Stock has been automatically converted into Common Stock) as of a
particular date (the "DETERMINATION DATE") shall mean:

                (a) If the net issue election is made in connection with and
        contingent upon the closing of the sale of the Company's Common Stock to
        the public in a public offering pursuant to a Registration Statement
        under the Securities Act of 1933 ("1933 ACT") (a "PUBLIC OFFERING"), and
        if the Company's Registration Statement relating to such Public Offering
        ("REGISTRATION STATEMENT") has been declared effective by the Securities
        and Exchange Commission, then the initial "Price to Public" specified in
        the final prospectus with respect to such offering multiplied by the
        number of shares of Common Stock into which each share of Preferred
        Stock is then convertible.

                (b) If the net issue election is not made in connection with and
        contingent upon a Public Offering, then as follows:

                        (i) If traded on a securities exchange or the Nasdaq
                National Market, the fair market value of the Common Stock shall
                be deemed to be the average of the closing or last reported sale
                prices of the Common Stock on such exchange or market over the
                five day period ending five business days prior to the
                Determination Date, and the fair market value of the Preferred
                Stock shall be deemed to be such fair market value of the Common
                Stock multiplied by the number of shares of Common Stock into
                which each share of Preferred Stock is then convertible;

                        (ii) If otherwise traded in an over-the-counter market,
                the fair market value of the Common Stock shall be deemed to be
                the average of the closing ask prices of the Common Stock over
                the five day period ending five business days prior to the
                Determination Date, and the fair market value of the Preferred
                Stock shall be deemed to be such fair market value of the Common
                Stock multiplied by the number of shares of Common Stock into
                which each share of Preferred Stock is then convertible; and

                        (iii) If there is no public market for the Common Stock,
                then fair market value shall be determined in good faith by the
                Company's Board of Directors.

        5. PARTIAL EXERCISE. This Warrant may be exercised in part, and the
Holder shall be entitled to receive a new warrant, which shall be dated as of
the date of this Warrant, covering the number of shares in respect of which this
Warrant shall not have been exercised.

        6. FRACTIONAL SHARES. In no event shall any fractional share of
Preferred Stock be issued upon any exercise of this Warrant. If, upon exercise
of this Warrant in its entirety, the Holder would, except as provided in this
SECTION 6, be entitled to receive a fractional share of Preferred Stock, then
the Company shall pay in lieu thereof, the Fair Market Value of such fractional
share in cash.

        7. EXPIRATION DATE; AUTOMATIC EXERCISE. This Warrant shall expire at the
close of business on April 30, 2006, and shall be void thereafter.
Notwithstanding the foregoing, this Warrant shall automatically be deemed to be
exercised in full pursuant to the provisions of SECTION 4 hereof, without any
further action on behalf of the Holder, immediately prior to the time this
Warrant would otherwise expire pursuant to the preceding sentence.

        8. RESERVED SHARES; VALID ISSUANCE. The Company covenants that it will
at all times from and after the date hereof reserve and keep available such
number of its authorized shares of Preferred Stock and Common Stock, $0.0001 par
value, of the Company (the "COMMON STOCK"), free from all preemptive or similar
rights therein, as will be sufficient to permit, respectively, the exercise of
this Warrant in full and the conversion into shares of Common Stock of all
shares of Preferred Stock receivable upon such exercise. The Company further
covenants that such shares as may be issued pursuant to such exercise and/or
conversion will, upon issuance, be duly



                                       2.

<PAGE>   65

and validly issued, fully paid and nonassessable and free from all taxes, liens
and charges with respect to the issuance thereof.

        9. STOCK SPLITS AND DIVIDENDS. If after the date hereof the Company
shall subdivide the Preferred Stock, by split-up or otherwise, or combine the
Preferred Stock, or issue additional shares of Preferred Stock in payment of a
stock dividend on the Preferred Stock, the number of shares of Preferred Stock
issuable on the exercise of this Warrant shall forthwith be proportionately
increased in the case of a subdivision or stock dividend, or proportionately
decreased in the case of a combination, and the Purchase Price shall forthwith
be proportionately decreased in the case of a subdivision or stock dividend, or
proportionately increased in the case of a combination.

        10. NO STOCKHOLDER RIGHTS. Except as expressly provided in this Warrant,
prior to exercise of this Warrant, the Holder shall not be entitled to any
rights of a stockholder with respect to the Shares, including without limitation
the right to vote such Shares, receive dividends or other distributions thereon,
exercise preemptive rights or be notified of stockholder meetings, and such
Holder shall not be entitled to any notice or other communication concerning the
business or affairs of the Company, provided, however, that nothing in this
SECTION 10 shall limit the right of the Holder to be provided the notices
required under the Warrant.

        11. MERGERS AND RECLASSIFICATIONS. If after the date hereof the Company
shall enter into any Reorganization (as hereinafter defined), then, as a
condition of such Reorganization, lawful provisions shall be made, and duly
executed documents evidencing the same from the Company or its successor shall
be delivered to the Holder, so that the Holder shall thereafter have the right
to purchase, at a total price not to exceed that payable upon the exercise of
this Warrant in full, the kind and amount of shares of stock and other
securities and property receivable upon such Reorganization by a holder of the
number of shares of Preferred Stock which might have been purchased by the
Holder immediately prior to such Reorganization, and in any such case
appropriate provisions shall be made with respect to the rights and interest of
the Holder to the end that the provisions hereof (including without limitation,
provisions for the adjustment of the Purchase Price and the number of shares
issuable hereunder and the provisions relating to the net issue election) shall
thereafter be applicable in relation to any shares of stock or other securities
and property thereafter deliverable upon exercise hereof. For the purposes of
this SECTION 11, the term "REORGANIZATION" shall mean and refer to (i) an
acquisition of the Company by another entity by means of a merger,
consolidation, or other transaction or series of related transactions resulting
in the exchange of the outstanding shares of the Company's capital stock such
that stockholders of the Company prior to such transaction own, directly or
indirectly, less than 50% of the voting power of the surviving entity, or (ii) a
sale or transfer of all or substantially all of the Company's asset to any other
person.

        12. CERTIFICATE OF ADJUSTMENT. Whenever the Purchase Price is adjusted,
as herein provided, the Company shall promptly deliver to the Holder a
certificate of the Company's chief financial officer setting forth the Purchase
Price after such adjustment and setting forth a brief statement of the facts
requiring such adjustment.

        13. NOTICES OF RECORD DATE, ETC. In the event of:

           (a) any taking by the Company of a record of the holders of any class
of securities for the purpose of determining the holders thereof who are
entitled to receive any dividend or other distribution, or any right to
subscribe for, purchase, sell or otherwise acquire or dispose of any shares of
stock of any class or any other securities or property, or to receive any other
right;

           (b) any reclassification of the capital stock of the Company, capital
reorganization of the Company, consolidation or merger involving the Company, or
sale or conveyance of all or substantially all of its assets; or

           (c) any voluntary or involuntary dissolution, liquidation or
winding-up of the Company;

then in each such event the Company will provide or cause to be provided to the
Holder a written notice thereof. Such notice shall be provided at least twenty
(20) business days prior to the date specified in such notice on which any such
action is to be taken.



                                       3.
<PAGE>   66


        14. REPRESENTATIONS, WARRANTIES AND COVENANTS. This Warrant is issued
and delivered by the Company and accepted by each Holder on the basis of the
following representations, warranties and covenants made by the Company:

            (a) The Company has all necessary authority to issue, execute and
deliver this Warrant and to perform its obligations hereunder. This Warrant has
been duly authorized issued, executed and delivered by the Company and is the
valid and binding obligation of the Company, enforceable in accordance with its
terms.

            (b) The shares of Preferred Stock issuable upon the exercise of this
Warrant have been duly authorized and reserved for issuance by the Company and,
when issued in accordance with the terms hereof, will be validly issued, fully
paid and nonassessable.

            (c) The issuance, execution and delivery of this Warrant do not, and
the issuance of the shares of Preferred Stock upon the exercise of this Warrant
in accordance with the terms hereof will not, (i) violate or contravene the
Certificate or by-laws, or to the Company's knowledge, any law, statute,
regulation, rule, judgment or order applicable to the Company, (ii) violate,
contravene or result in a breach or default under any contract, agreement or
instrument to which the Company is a party or by which the Company or any of its
assets are bound or (iii) require the consent or approval of or the filing of
any notice or registration with any person or entity.

            (d) As long as this Warrant is, or any shares of Preferred Stock
issued upon exercise of this Warrant or any shares of Common Stock issued upon
conversion of such shares of Preferred Stock are, issued and outstanding, the
Company will provide to the Holder the financial and other information described
in that certain Lease Line Schedule No. 01 to Master Equipment Lease Agreement
No. 219 between the Company and Lighthouse Capital Partners II, L.P. dated as of
May 5, 1999.

            (e) As of the date hereof, the authorized capital stock of the
Company consists of (i) 19,000,000 shares of Common Stock, none of which are
issued and outstanding and 21,539 shares are reserved for issuance upon the
exercise of this Warrant and the conversion of the Preferred Stock, (ii)
5,686,573 shares of Series A Preferred Stock, all of which are issued and
outstanding, and (iii) 4,130,000 shares of Series B Preferred Stock, of which
3,970,000 are issued and outstanding shares and 21,539 shares are reserved for
issuance upon the exercise of this Warrant. Attached hereto as EXHIBIT C is a
capitalization table summarizing the capitalization of the Company, including,
without limitation, the current Conversion Price of the Series B Preferred
Stock.

        15. INVESTORS' RIGHTS AGREEMENT. The Company agrees that, upon the next
amendment of that certain Investors' Rights Agreement by and among the Company,
the Investors and the Founders listed therein dated as of December 17, 1998 (the
"INVESTORS' RIGHTS AGREEMENT"), it will use its best efforts to effect such
amendment so that the Holder shall be an Investor within the meaning of such
Investors' Rights Agreement.

        16. RIGHT OF FIRST REFUSAL. Subject to the terms and conditions
contained in this SECTION 16, the Company agrees that the holder of this Warrant
has the right of first refusal to purchase its pro rata portion of any New
Securities (as defined in SECTION 16(a) below) which the Company may, from time
to time, propose to sell and issue. A holder's pro rata portion for purposes of
this SECTION 16 is the ratio that (x) the sum of the number of shares of the
Company's Common Stock then issued or issuable to the holder (including upon
conversion of any Preferred Stock held by the holder and upon exercise of this
Warrant and conversion of the Shares issued thereupon) bears to (y) the sum of
the total number of shares of Company's Common Stock then outstanding, the
number of shares of the Company's Common Stock issuable upon conversion of the
Preferred Stock then outstanding, and the number of shares of the Company's
Common Stock issuable to the holder upon exercise of this Warrant and conversion
of the Shares issued thereupon.

            (a) DEFINITION OF NEW SECURITIES. Except as set forth below, "NEW
SECURITIES" shall mean any shares of capital stock of the Company, including
Common Stock and Preferred Stock, whether now authorized or not, and rights,
options or warrants to purchase said shares of Common Stock or Preferred Stock,
and securities of any type whatsoever that are, or may become, convertible into
or exercisable for said shares of Common Stock or Preferred Stock.
Notwithstanding the foregoing, "New Securities" does not include: (i) Common
Stock issuable upon conversion of any Preferred Stock outstanding as of the
grant date; (ii) securities offered to the public generally pursuant to a
registration statement under the Securities Act; (iii) securities issued
pursuant to the



                                       4.
<PAGE>   67


acquisition of another corporation by the Company by merger, purchase of
substantially all of the assets or shares or other reorganization; (iv) shares
of the Company's Common Stock or related options convertible into or exercisable
for such Common Stock issued to employees, officers and directors of, and
consultants to, the Company, pursuant to any compensatory benefit plan; (v)
stock issued pursuant to any rights or agreements, including, without
limitation, convertible securities, options and warrants, provided that the
Company shall have complied with the right of first refusal established by this
SECTION 16 with respect to the initial sale or grant by the Company of such
rights or agreements; or (vi) stock issued in connection with any stock split,
reverse stock split, stock dividend, combination or recapitalization by the
Company.

            (b) NOTICE OF RIGHT. In the event the Company proposes to undertake
an issuance of New Securities, it shall give the holder written notice of its
intention, describing the type of New Securities and the price and terms upon
which the Company proposes to issue the same. The holder shall have fifteen (15)
days from the date of receipt of any such notice to agree to purchase shares of
such New Securities (up to the amount referred to in this SECTION 16), for the
price and upon the terms specified in the notice, by giving written notice to
the Company and stating therein the quantity of New Securities to be purchased.

            (c) EXERCISE OF RIGHT. If the holder exercises its right of first
refusal hereunder, the closing of the purchase of the New Securities with
respect to which such right has been exercised shall take place within ninety
(90) calendar days after the holder gives notice of such exercise, which period
of time shall be extended in order to comply with applicable laws and
regulations. Upon exercise of such right of first refusal, the Company and the
holder shall be legally obligated to consummate the purchase contemplated
thereby and shall use their best efforts to secure any approvals required in
connection therewith.

            (d) LAPSE AND REINSTATEMENT OF RIGHT. In the event the holder fails
to exercise the right of first refusal provided in this SECTION 16 within said
fifteen (15) day period, the Company shall have ninety (90) days thereafter to
sell or enter into an agreement (pursuant to which the sale of New Securities
covered thereby shall be closed, if at all, within sixty (60) days from the date
of said agreement) to sell the New Securities not elected to be purchased by the
holder at the price and upon the terms no more favorable to the purchasers of
such securities than specified in the Company's notice. In the event the Company
has not sold the New Securities or entered into an agreement to sell the New
Securities within said ninety (90) day period (or sold and issued New Securities
in accordance with the foregoing within sixty (60) days from the date of said
agreement), the Company shall not thereafter issue or sell any New Securities
without first offering such securities to the holder in the manner provided
above.

            (e) ASSIGNMENT. The right of the holder to purchase any part of the
New Securities may be assigned in whole or in part to any partner, subsidiary,
affiliate or shareholder of the holder.

            (f) TERMINATION OF RIGHT OF FIRST REFUSAL. The right of first
refusal granted under SECTION 16 shall terminate on and be of no further force
or effect upon the closing of a firmly underwritten public offering of the
securities of the Company.

        17. AMENDMENT. The terms of this Warrant may be amended, modified or
waived only with the written consent of the Holder and the Company.

        18. REPRESENTATIONS AND COVENANTS OF THE HOLDER. This Preferred Stock
Purchase Warrant has been entered into by the Company in reliance upon the
following representations and covenants of the Holder, which by its execution
hereof the Holder hereby confirms:

            (a) INVESTMENT PURPOSE. The right to acquire Preferred Stock
issuable upon exercise of the Holder's rights contained herein or Common Stock
issuable upon conversion thereof (the "CONVERSION SHARES") will be acquired for
investment and not with a view to the sale or distribution of any part thereof,
and the Holder has no present intention of selling or engaging in any public
distribution of the same except pursuant to a registration or exemption. The
Holder further represents that such Holder does not 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 Preferred Stock or Conversion Shares.



                                       5.
<PAGE>   68


            (b) ACCREDITED INVESTOR. Holder is an "accredited investor" within
the meaning of the Securities and Exchange Rule 501 of Regulation D, as
presently in effect.

            (c) PRIVATE ISSUE. The Holder understands (i) that the Preferred
Stock issuable upon exercise of the Holder's rights contained herein and the
Conversion Shares is not registered under the 1933 Act or qualified under
applicable state securities laws on the ground that the issuance contemplated by
this Warrant will be exempt from the registration and qualifications
requirements thereof, and (ii) that the Company's reliance on such exemption is
predicated on the representations set forth in this SECTION 18.

            (d) FINANCIAL RISK. The Holder is an investor in securities of
companies in the development stage and has such knowledge and experience in
financial and business matters as to be capable of evaluating the merits and
risks of its investment and has the ability to bear the economic risks of its
investment.

            (e) DISCLOSURE OF INFORMATION. The Holder believes it has received
all the information it considers necessary or appropriate for deciding whether
to purchase the Warrant and the Preferred Stock issuable upon exercise thereof.
Such Holder further represents that it has had the opportunity to ask questions
and receive answers from the Company regarding the terms and conditions of the
Preferred Stock and the business, properties, prospects and financial condition
of the Company.

        19. NOTICES, TRANSFERS, ETC.

            (a) Any notice or written communication required or permitted to be
given to the Holder may be given by certified mail or delivered to the Holder at
the address most recently provided by the Holder to the Company.

            (b) Subject to compliance with applicable federal and state
securities laws, this Warrant may be transferred by the Holder with respect to
any or all of the shares purchasable hereunder. Upon surrender of this Warrant
to the Company, together with the assignment notice annexed hereto duly
executed, for transfer of this Warrant as an entirety by the Holder, the Company
shall issue a new warrant of the same denomination to the assignee. Upon
surrender of this Warrant to the Company, together with the assignment hereof
properly endorsed, by the Holder for transfer with respect to a portion of the
shares of Preferred Stock purchasable hereunder, the Company shall issue a new
warrant to the assignee, in such denomination as shall be requested by the
Holder hereof, and shall issue to such Holder a new warrant covering the number
of shares in respect of which this Warrant shall not have been transferred.

            (c) In case this Warrant shall be mutilated, lost, stolen or
destroyed, the Company shall issue a new warrant of like tenor and denomination
and deliver the same (i) in exchange and substitution for and upon surrender and
cancellation of any mutilated Warrant, or (ii) in lieu of any Warrant lost,
stolen or destroyed, upon receipt of an affidavit of the Holder or other
evidence reasonably satisfactory to the Company of the loss, theft or
destruction of such Warrant

        20. NO IMPAIRMENT. The Company will not, by amendment of its Certificate
or through any reclassification, capital reorganization, consolidation, merger,
sale or conveyance of assets, dissolution, liquidation, issue or sale of
securities or any other voluntary action, avoid or seek to avoid the observance
of performance of any of the terms of this Warrant, but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the Holder.

        21. GOVERNING LAW. The provisions and terms of this Warrant shall be
governed by and construed in accordance with the internal laws of the State of
California.

        22. SUCCESSORS AND ASSIGNS. This Warrant shall be binding upon the
Company's successors and assigns and shall inure to the benefit of the Holder's
successors, legal representatives and permitted assigns.

        23. BUSINESS DAYS. If the last or appointed day for the taking of any
action required or the expiration of any rights granted herein shall be a
Saturday or Sunday or a legal holiday in California, then such action may be


                                       6.
<PAGE>   69


        taken or right may be exercised on the next succeeding day which is not
a Saturday or Sunday or such a legal holiday.

        24. QUALIFYING PUBLIC OFFERING. If the Company shall effect a firm
commitment underwritten public offering of shares of Common Stock which results
in the conversion of the Preferred Stock into Common Stock pursuant to the
Certificate in effect immediately prior to such offering, then, effective upon
such conversion, this Warrant shall change from the right to purchase shares of
Preferred Stock to the right to purchase shares of Common Stock, and the Holder
shall thereupon have the right to purchase, at a total price equal to that
payable upon the exercise of this Warrant in full, the number of shares of
Common Stock which would have been receivable by the Holder upon the exercise of
this Warrant for shares of Preferred Stock immediately prior to such conversion
of such shares of Preferred Stock into shares of Common Stock, and in such event
appropriate provisions shall be made with respect to the rights and interest of
the Holder to the end that the provisions hereof (including, without limitation,
the provisions for the adjustment of the Purchase Price and of the number of
shares purchasable upon exercise of this Warrant and the provisions relating to
the net issue election) shall thereafter be applicable to any shares of Common
Stock deliverable upon the exercise hereof.

        25. VALUE. The Company and the Holder agree that the value of this
Warrant on the date of grant is $100.



Dated:  May __, 1999                       CHEMCONNECT, INC.



                                           By: /s/ PHILIP J. RINGO
                                              ------------------------------
                                           Name: Phil J. Ringo
                                                 ------------------------------
                                           Title: President and COO
                                                  -----------------------------


        [CORPORATE SEAL]

Attest:


---------------------------------



                                       7.
<PAGE>   70

                                  SUBSCRIPTION


To: ___________________________________________________     Date:______________

        The undersigned hereby subscribes for ____________ shares of Preferred
Stock covered by this Warrant. The certificate(s) for such shares shall be
issued in the name of the undersigned or as otherwise indicated below:


                                      Signature:
                                                -------------------------------

                                      Name for Registration:
                                                            -------------------

                                      Mailing Address:
                                                      -------------------------

                                      -----------------------------------------



                            NET ISSUE ELECTION NOTICE

To: ___________________________________________________     Date:______________


        The undersigned hereby elects under SECTION 4 to surrender the right to
purchase __________ shares of Preferred Stock pursuant to this Warrant. The
certificate(s) for such shares issuable upon such net issue election shall be
issued in the name of the undersigned or as otherwise indicated below:


                                      Signature:
                                                -------------------------------

                                      Name for Registration:
                                                            -------------------

                                      Mailing Address:
                                                      -------------------------

                                      -----------------------------------------




<PAGE>   71

                                   ASSIGNMENT


        For value received ______________________________ hereby sells, assigns
and transfers unto ____________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________


            [Please print or typewrite name and address of Assignee]
________________________________________________________________________________
the within Warrant, and does hereby irrevocably constitute and appoint
____________________________________ its attorney to transfer the within Warrant
on the books of the within named Company with full power of substitution on the
premises.


Dated:_______________________


In the Presence of:


_____________________________




<PAGE>   72



                                    EXHIBIT A

                      RESTATED CERTIFICATE OF INCORPORATION


                               See attached pages.





<PAGE>   73


                                    EXHIBIT B

                              CAPITALIZATION TABLE

                               See attached pages.