<PAGE>

EXHIBIT 10.35
                           STOCK PURCHASE AGREEMENT


          STOCK PURCHASE AGREEMENT dated as of June 4, 1999 (the "Agreement"),
by and among TK HOLDINGS, INC., a Canadian corporation ("TK Holdings"), located
at 365 Bay Street, 10th Floor, Toronto, Ontario, CANADA MSH 2V2, and Mark
Valentine ("Valentine"; each of Valentine and TK Holdings, an "Investor", and
collectively, the "Investors"), UNIVERSAL TRADING TECHNOLOGIES CORPORATION, a
corporation organized and existing under the laws of the State of Delaware (the
"Company") located at 1900 Market Street, Suite 701, Philadelphia, Pennsylvania
19103, and THE ASHTON TECHNOLOGY GROUP, INC. ("ATG") located at 1900 Market
Street, Suite 701, Philadelphia, Pennsylvania 19103. The Investors, the Company
and ATG together are referred to collectively as the "Parties" and each, a
"Party".

          WHEREAS, the Parties desire that, upon the terms and subject to the
conditions contained herein, the Company shall issue and sell to the Investors,
as provided herein, and the Investors shall purchase (a) certain shares of the
Company's Series TK Convertible Preferred Stock (the "Preferred Stock") and (b)
two (2) warrants to purchase shares of the common stock of ATG, par value $.01
per share ("ATG Common Stock") (each a "Warrant" and collectively, the
"Warrants") as more fully described herein (together, the "Securities") for an
aggregate purchase price of $2,000,000 (the "Aggregate Purchase Price"); and

          WHEREAS, such investment will be made in reliance upon the provisions
of Section 4(2) ("Section 4(2)") and Regulation D ("Regulation D") of the
Securities Act of 1933, as amended (the "Securities Act") and the regulations
promulgated thereunder, and/or upon such other exemption from the registration
requirements of the Securities Act as may be available with respect to the offer
and sale of the Securities to be made hereunder; and

          NOW, THEREFORE, the Parties hereto agree as follows:

                                   ARTICLE I
                      Purchase and Sale of the Securities

          Section I.1  Sale and Issuance of the Securities.

          The Company agrees to sell and the Investors agrees to purchase from
the Company: (a) 145,700 shares of the Preferred Stock, and (b) two (2)
Warrants, for an aggregate purchase price of $2,000,000 at the Closing (as
hereinafter defined).
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          Section I.2  Terms of Preferred Stock.

          The rights, privileges and preferences of the Preferred Stock shall be
as stated in the Certificate of Designation for the Preferred Stock, the form of
which is attached hereto as Exhibit A, as filed with the appropriate offices of
the State of Delaware.

          Section I.3  Terms of the Warrant.

          The rights, privileges and preferences of the Warrants shall be stated
in the Stock Purchase Warrants, the forms of which are attached hereto as
Exhibits B-1 and B-2.

          Section I.4  Closing.

          The purchase and sale of the Securities shall take place at 9:00 a.m.,
Eastern Standard Time, on June 4, 1999 (the "Closing Date") at the offices of
Ballard Spahr Andrews & Ingersoll, LLP, 1735 Market Street, 51st Floor,
Philadelphia, PA 19103, or at such other place as the Parties mutually agree
upon orally or in writing (which time and place are designated as the
"Closing").  At the Closing, the Parties shall complete each of the following
conditions:

          (1) The execution and delivery by the Company, ATG and the Investors
of this Agreement, and all Exhibits and Attachments hereto;

          (2) The delivery into escrow by the Company of certificates
representing the Securities;

          (3) The delivery into escrow by the Investors of good cleared funds in
the amount of $2,000,000 as payment for the Securities;

          (4) The delivery of evidence of the filing by the Company of the
Certificate of Designation for the Preferred Stock (the "Certificate of
Designation"), with the appropriate offices of the State of Delaware.

          (5) The execution and delivery by the Company and the Investors of a
letter of intent in regard to a joint venture proposed to be formed by the
Parties in the form satisfactory to each Party.


                                  ARTICLE II
                Representations and Warranties of the Investors

          Each of the Investors hereby represents and warrants to the Company
that the following are true and correct as of the Closing Date:

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          Section II.1   Organization and Authorization. TK Holdings is duly
incorporated or organized and validly existing in the country of its
incorporation or organization and each of the Investors has all requisite power
and authority to purchase and hold the Securities to be issued hereunder. The
decision to invest and the execution and delivery of this Agreement by the
Investors, the performance by each of the Investors of its obligations hereunder
and the consummation by the Investors of the transactions contemplated hereby
have been duly authorized and require no other action or proceeding on the part
of the Investors. The undersigned executing this Agreement on behalf of TK
Holdings has all right, power and authority to execute and deliver this
Agreement on behalf of TK Holdings. This Agreement has been duly executed and
delivered by each of the Investors and, assuming the execution and delivery
hereof and acceptance thereof by the Company and ATG, will constitute the legal,
valid and binding obligation of each of the Investors, enforceable against each
of the Investors in accordance with its terms.

          Section II.2  Sophisticated Investors.  Each of the Investors is a
sophisticated investor (as described in Rule 506(b)(2)(ii) of Regulation D) and
an accredited investor (as defined in Rule 501 of Regulation D), and each of the
Investors has such experience in business and financial matters that it is
capable of evaluating the merits and risks of, and bearing the economic risks
entailed by, an investment in the Securities and protecting its interest in
connection with this transaction. Each of the Investors acknowledges that an
investment in the Securities is speculative and involves a high degree of risk.

          Section II.3  Independent Counsel.  Each of the Investors acknowledges
that it has been advised to consult with its own attorney regarding legal
matters concerning the Company and ATG and to consult with its tax advisor
regarding the tax consequences of acquiring the Securities issuable hereunder.
Each of the Investors acknowledges that it has been advised to consult with its
own attorney regarding any laws of any country other than the United States.

          Section II.4  No Public Market.  Each of the Investors acknowledges
that it is aware that there is no public market for the Preferred Stock, the
Warrants or the Common Stock underlying the Preferred Stock. Each of the
Investors acknowledges that it is aware that a public market may not develop for
the Preferred Stock, the Warrants or the Common Stock underlying the Preferred
Stock.

          Section II.5  No Registration.  Each of the Investors understands that
neither the Preferred Stock, the Common Stock underlying the Preferred Stock,
the Warrants nor the ATG Common Stock issuable upon the exercise of the Warrants
have been registered under the Securities Act, any state securities law or any
other securities laws but are being offered and sold to it in reliance upon
specific exemptions from the registration requirements of the Securities Act and
certain state securities laws and that the Company is relying upon the truth and
accuracy of the representations, warranties, agreements, acknowledgments and
understandings of each of the

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Investors set forth herein in order to determine the applicability of such
exemptions and the suitability of each of the Investors to acquire the
securities hereunder.

          Section II.6  Investment Intent.  Each of the Investors is entering
into this Agreement solely for its own account and each of the Investors has no
present intention or arrangement (whether or not legally binding) at any time to
sell or distribute any of the Securities to or through any person or entity.
Each of the Investors understands and agrees that it may bear the economic risk
of its investment in the Securities for an indefinite period of time.

          Section II.7  Transfer Restrictions Regarding the Preferred Stock.
The Investors understands that the Securities are characterized as "restricted
securities" under the United States securities laws inasmuch as they are being
acquired from the Company in a transaction not involving a public offering and
that under the Securities Act and applicable regulations the securities may be
resold without registration under the Securities Act only in certain limited
circumstances and only with the prior approval by the Company. In this regard,
each of the Investors represent that he or it is familiar with Rule 144 under
the Securities Act, as presently in effect, and understands the resale
limitations imposed thereby and by the Securities Act.

          Section II.8  Registration Rights.   The Investors understand that
they shall have no registration rights with respect to the Securities other than
those set forth in Section 5.1 of the Agreement and or may be provided in the
Warrants.

          Section II.9  No Advertisements.  None of the Investors are entering
into this Agreement as a result of, or subsequent to, any advertisement,
article, notice or other communication published in any newspaper, magazine, or
similar media or broadcast over television or radio, or presented at any seminar
or meeting.

          Section II.10  Foreign Investors.  Each of the Investors that is not a
United States person hereby represents that he or it has satisfied himself or
itself as to the full observance of the applicable laws of his or its country
and/or jurisdiction in connection with any invitation to subscribe for the
Securities or any use of the Agreement, including (i) the legal requirements
within his or its country and/or jurisdiction for the purchase of the
Securities, (ii) any foreign exchange restrictions applicable to such purchase,
(iii) any government or other consents that may need to be obtained, and (iv)
the income tax and other tax consequences, if any, that may be relevant to the
purchase, holding, redemption, sale, or transfer of the Securities. Each of the
Investors' subscription and payment for, and his or its continued beneficial
ownership of, the Securities, will not violate any applicable securities or
other laws of its country and/or jurisdiction.

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                                  ARTICLE III
                 Representations and Warranties of the Company

          The Company hereby represents and warrants to the Investors that the
following are true and correct as of the Closing Date:

          Section III.1  Organization; Qualification. The Company is a
corporation duly organized and validly existing under the laws of the State of
Delaware and is in good standing under such laws. The Company has all requisite
corporate power and authority to own, lease and operate its properties and
assets, and to carry on its business as presently conducted.

          Section III.2  Capitalization. The authorized capital stock of the
Company consists of 40,000,000 shares of Common Stock, $.01 par value per share,
of which 24,280,592 are outstanding, 2,000,000 shares of non-voting Preferred
Stock, $.01 par value, of which none are outstanding. All issued and outstanding
shares of Common Stock and Preferred Stock have been duly authorized and validly
issued and are fully paid and nonassessable.

          Section III.3  Authorization. The Company has all requisite corporate
right, power and authority to execute and deliver this Agreement and to
consummate the transactions contemplated hereby. All corporate action on the
part of the Company, its directors and stockholders necessary for the
authorization, execution, delivery and performance of this Agreement by the
Company, the authorization, sale, issuance and delivery of the securities
issuable hereunder and the performance of the Company's obligations hereunder
have been taken. This Agreement has been duly executed and delivered by the
Company and constitutes a legal, valid and binding obligation of the Company
enforceable in accordance with its terms. Upon their issuance and delivery
pursuant to this Agreement, the Securities will be validly issued, fully paid
and nonassessable and will be free of any liens or encumbrances other than those
created hereunder or by the actions of the Investors; provided, however, that
the Securities are subject to restrictions on transfer under federal and/or
state securities laws. The issuance and sale of the Securities hereunder will
not give rise to any preemptive right or right of first refusal or right of
participation on behalf of any person.

          Section III.4  Offering.  Subject in part to the truth and accuracy of
the Investors' representations as set forth in Article II of this Agreement, the
offer, sale and issuance of the Securities as contemplated by this Agreement are
exempt from the registration requirements of the Securities Act, and neither the
Company nor any authorized agent acting on its behalf will purposefully take any
action hereafter that would cause the loss of such exemption.

          Section III.5  No Conflict. The execution and delivery of this
Agreement do not, and the consummation of the transactions contemplated hereby
will not, conflict with or result in any violation of any provision of the
Company's Certificate of Incorporation, bylaws or any amendments thereto. The
execution and delivery of this Agreement do not, and the consummation of the
transactions contemplated hereby will not, conflict with or result in any

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violation of, or default, or give rise to a right of termination, cancellation
or acceleration of any material obligation or to a loss of any material benefit,
under any material mortgage, indenture, lease or other agreement or instrument,
permit, concession, franchise, license, judgment, order, decree statute, law,
ordinance, rule or regulation applicable to the Company, its properties or
assets and which would have a material adverse effect on the Company's business
and financial condition.

          Section III.6  No Undisclosed Liabilities or Events. With the
exception of certain contingent liabilities set forth on Schedule 3.6 hereto,
the Company has no liabilities or obligations other than those incurred in the
ordinary course of the Company's business, which individually or in the
aggregate, do not or would not have a material adverse effect on the properties,
business, condition (financial or otherwise), results of operations or prospects
of the Company. No event or circumstances have occurred or exist with respect to
the Company or its properties, business, condition (financial or otherwise),
results of operations or prospects, which, under applicable law, rule or
regulation, requires public disclosure or announcement prior to the date hereof
by the Company, but which has not been so publicly announced or disclosed.

          Section III.7  No Default. The Company is not in default in the
performance or observance of any material obligation, agreement, covenant or
condition contained in any indenture, mortgage, deed of trust or other material
instrument or agreement to which it is a Party or by which it is or its property
is bound, or any decree, judgment, order, rule or regulation of any court or
governmental agency or body having jurisdiction over the Company or its
properties, in each case which default, lien or charge is likely to cause a
material adverse effect on the Company's business and financial condition.

          Section III.8  Litigation.  With the exception of certain potential
litigation set forth on Schedule 3.8 hereto, there is no action, proceeding or
investigation pending, or to the Company's knowledge threatened, against the
Company which might result, either individually or in the aggregate, in any
material adverse change in the business, prospects, financial conditions or
operations of the Company.

          Section III.9  Title to Assets.  The Company has good and marketable
title to all properties and material assets as owned by it, free and clear of
any pledge, lien, security interest, encumbrance, claim or equitable interest
other than such as are not material to the business of the Company.

          Section III.10  Required Governmental Permits.  The Company and its
subsidiaries are in possession of and operating in compliance with all
authorizations, licenses, certificates, consents, orders and permits from state,
federal and other regulatory authorities which are material to the conduct of
its business, all of which are valid and in full force and effect.

          Section III.11  Governmental Consent.  No consent, approval or
authorization of or designation, declaration or filing with any governmental
authority on the part of the Company

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is required in connection with the valid execution and delivery of this
Agreement, or the offer, sale or issuance of the Securities hereunder, or the
consummation of any other transaction contemplated hereby.

          Section III.12  Other Outstanding Securities/Financing Restrictions.
Other than the Common Stock, Preferred Stock, and warrants and options disclosed
in Section 3.12 hereto, there are no other outstanding securities, debt or
equity presently convertible into Common Stock.

          Section III.13  Dilution. The Company is aware and acknowledges that
conversion of the Preferred Stock and the issuance of Common Stock underlying
the Preferred Stock, could cause dilution to existing shareholders and could
significantly increase the outstanding number of shares of the Company's Common
Stock.


                                  ARTICLE IV
                          Covenants of the Investors

          Section IV.1  Conversion Holding Period/Conversion Limits.  The
Investors warrants and agrees that it shall not exercise its right to convert
the Preferred Stock as set forth in the Certificate of Designation until the
earlier of (i) April 30, 2001; or (ii) upon the occurrence of a Change of
Control (as defined herein) of the Company (together the "Holding Period").

          Section IV.2  Mandatory Conversion.  In the event the Preferred Stock
has not been converted by or before April 30, 2004, the Investors's Conversion
Rights as set forth in the Certificate of Designation shall expire and the
Company shall not be obligated under any provisions of this Agreement to issue
the Common Stock underlying the Preferred Stock.

          Section IV.3  Short Selling.  The Investors hereby covenants that it
shall not engage in any short sales of the Company's Common Stock or the ATG
Common Stock.


                                   ARTICLE V
                       Covenants of the Company and ATG

          Section V.1  Registration Rights.  The Company covenants and agrees
that it shall register the Common Stock issuable upon conversion of the
Preferred Stock pursuant to the Securities Act, upon written demand by the
Investors, on one occasion following the fourth (4th) anniversary of the Closing
Date. Notwithstanding the preceding sentence, the Company covenants and agrees
that it shall register such Common Stock pursuant to the Securities Act, upon
written demand by the Investors, at such time that the Company shall engage in
an initial public offering of its Common Stock provided, however, that the
amount of the Common Stock

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registered pursuant to this sentence shall be subject to adjustment by any
underwriter engaged by the Company, at its sole discretion, in connection with
any such initial public offering.

          Section V.2  Amendment of Charter or Issuance of Senior Preferred
Stock. The Company covenants and agrees that it shall not (i) amend the
Certificate of Incorporation of the Company or the Certificate of Designation in
any manner that adversely affects the rights of the Investors or (ii) authorize
the issuance of preferred stock ranking senior to the Preferred Stock, without
the prior approval of a majority-in-interest of the Investors; provided,
however, that such approval shall not be unreasonably withheld.

          Section V.3  Reservation of Common Stock.

          V.3.1  Company Common Stock.  As of the date hereof, the Company has
authorized and reserved, and the Company shall continue to reserve and keep
available at all times, free of preemptive rights, shares of Common Stock for
the purpose of enabling the Company to satisfy any obligation to issue the
Common Stock upon the conversion of the Preferred Stock. The number of shares of
Common Stock so reserved shall be increased or decreased to provide for any
adjustment to the number of shares of Common Stock issuable upon the conversion
of the Preferred Stock as contemplated in the Certificate of Designation.

          V.3.2  ATG Common Stock.  As of the date hereof, ATG has authorized
and reserved and ATG shall continue to reserve and keep available at all times,
free of preemptive rights, shares of ATG Common Stock for the purpose of
enabling ATG to satisfy its obligation to issue the ATG Common Stock pursuant to
the Warrant and pursuant to Section 5.10 hereof. The number of shares of ATG
Common Stock so reserved shall be increased or decreased to accommodate any anti
dilution protection in the Warrants.

          Section V.4  Legends. The certificates evidencing the Common Stock to
be issued to the Investors upon conversion of the Preferred Stock and the
certificates evidencing the ATG Common Stock to be issued to the Investors upon
exercise of the Warrants shall be free of legends, except as set forth in
Article VII.

          Section V.5  Corporate Existence. The Company will take all steps
necessary to preserve and continue the corporate existence of the Company.

          Section V.6  Change of Control.

          V.6.1  Assumption of Obligations.  The Company shall not, at any time
after the date hereof, effect any Change of Control unless the resulting
successor or acquiring entity (if not the Company) assumes by written instrument
the Company's obligations pursuant to this Agreement.

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          V.6.2  Definition of Change of Control.  A "Change of Control" shall
mean: (a) the consolidation or merger of the Company or any affiliate of the
Company holding or controlling a majority of the assets relating to the business
of the Company with or into any third party; (b) the assignment, sale, transfer,
lease or other disposition of all or substantially all of the assets of the
Company and its affiliates taken as a whole; or (c) the acquisition by any third
party or group of third parties acting in concert, of beneficial ownership of
shares of greater than fifty percent (50%) of the voting stock of the Company.

          Section V.7  Conversion of the Preferred Stock. The Company agrees
that it shall permit the Investors to exercise their right to convert the
Preferred Stock by telecopying an executed and completed notice of conversion (a
"Notice of Conversion") to the Company and delivering the original Notice of
Conversion and the certificate representing the Preferred Stock to the Company
by express courier. Each business date on which a Notice of Conversion is
telecopied to and received by the Company in accordance with the provisions
hereof shall be deemed a conversion date (the "Conversion Date"). The Company
will transmit the certificates representing shares of Common Stock issuable upon
conversion of any Preferred Stock (together with the certificates representing
the Preferred Stock not so converted) to the Investors via express courier, by
electronic transfer or otherwise within five (5) business days after the
conversion date if the Company has received the original Notice of Conversion
and Preferred Stock certificate being so converted by such date. The Investors
will be entitled to revoke the relevant Notice of Conversion by delivering a
notice to such effect to the Company within forty-eight (48) hours after receipt
of the earliest of the Notice of Conversion to the Company by telecopy or
express carrier whereupon the Company and the Investors shall each be restored
to their respective positions immediately prior to delivery of such Notice of
Conversion.

          Section V.8  Exercise of Warrant. The Company and ATG agree they shall
permit the Investors to exercise their right to exercise the Warrants by
telecopying an executed and completed notice of exercise (a "Notice of
Exercise") to ATG and delivering the original Notice of Exercise and the
certificate representing the Warrant to ATG by express courier. Each business
date on which a Notice of Exercise is telecopied to and received by ATG in
accordance with the provisions hereof shall be deemed an exercise date (the
"Exercise Date"). ATG will transmit the certificates representing shares of ATG
Common Stock issuable upon exercise of each of the Warrants (together with the
certificates representing the portion of the Warrants not so exercised) to the
applicable Investor via express courier, by electronic transfer or otherwise
within five (5) business days after the exercise date if ATG has received the
original Notice of Exercise and Warrants being so exercised by such date. The
applicable Investor will be entitled to revoke the relevant Notice of Exercise
by delivering a notice to such effect to ATG within forty-eight (48) hours after
receipt of the earliest of the Notice of Exercise to ATG by telecopy or express
carrier whereupon ATG and the Investors shall each be restored to their
respective positions immediately prior to delivery of such Notice of Exercise.

          Section V.9  Deliveries.  The Notice of Conversion and Preferred Stock
representing the portion of the shares converted shall be delivered to the
Company as set forth in

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Section 9.1 hereto. The shares of Common Stock issuable upon conversion of the
Preferred Stock and the certificate for any Preferred Stock not converted shall
be delivered to the Investors as set forth in Section 9.1 hereto. The Notice of
Exercise and Warrant representing the portion of the Warrant exercised shall be
delivered to ATG as set forth in Section 9.1. The shares of ATG Common Stock
issuable upon exercise of the Warrant and any certificate for any portion of the
Warrant not exercised shall be delivered to the Investors as set forth in
Section 9.1 hereto.

          Section V.10  Exchange Rights.  ATG and the Investors covenant and
agree that beginning on May 1, 2001 and for thirty-one (31) days thereafter each
of the Investors may at its or his option surrender to ATG each share of
Preferred Stock issued pursuant to this Agreement and held by such Investor at
such time in exchange for 1.83 shares of ATG Common Stock pursuant to an
exchange agreement, with typical representation and warranties, including those
similar to those made by the Investors in Article II hereof.

                                  ARTICLE VI
                                Indemnification

          Section VI.1  Indemnification.  Each of the Parties agrees to
indemnify the other Parties and to hold the other Parties harmless from and
against any and all losses, damages, liabilities, costs and expenses (including
reasonable attorneys' fees) which the other may sustain or incur in connection
with the breach by the indemnifying Party of any representation, warranty or
covenant made by it in this Agreement.


                                  ARTICLE VII
                                    Legends

          Section VII.1  Legends. Unless otherwise provided below, each
certificate representing the Securities and Common Stock to be issued upon
conversion of the Preferred Stock or exercise of the Warrants will bear the
following legend (the "Legend"):

          THE SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
          UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES
          ACT"), OR ANY OTHER APPLICABLE SECURITIES LAWS AND HAVE BEEN ISSUED IN
          RELIANCE UPON AN EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE
          SECURITIES ACT AND SUCH OTHER SECURITIES LAWS. NEITHER THIS SECURITY
          NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD,
          ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED, HYPOTHECATED OR OTHERWISE
          DISPOSED OF, EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT
          UNDER THE SECURITIES ACT OR PURSUANT TO A

                                       10
<PAGE>

          TRANSACTION THAT IS EXEMPT FROM, OR NOT SUBJECT TO, SUCH REGISTRATION.

          Section VII.2  Investors' Compliance. Nothing in this Article shall
affect in any way the Investors' obligations under any agreement to comply with
all applicable securities laws upon resale of the Common Stock.

                                 ARTICLE VIII
                          Choice of Law/Jurisdiction

          Section VIII.1  Choice of Law; Venue; Jurisdiction. This Agreement
will be construed and enforced in accordance with and governed by the laws of
the State of New York, except for matters arising under the Securities Act,
without reference to principles of conflicts of law. Each Party hereby agrees
that if another Party to this Agreement obtains a judgment against another Party
arising from a dispute involving this Agreement, the Party which obtained such
judgment may enforce such judgment by summary judgment or other procedure not
requiring trial on the merits in the courts of any country having jurisdiction
over the Party against whom such judgment was obtained, and each Party hereby
waives any defenses available to it under local law and agrees to the
enforcement of such a judgment. Each Party to this Agreement irrevocably
consents to the service of process in any such proceeding by the mailing of
copies thereof by registered or certified mail, postage prepaid, to such Party
at its address set forth herein. Nothing herein shall affect the right of any
Party to serve process in any other manner permitted by law.


                                  ARTICLE IX
                                    Notices

          Section IX.1   Notices. All notices, demands, requests, consents,
approvals, and other communications required or permitted hereunder shall be in
writing and, unless otherwise specified herein, shall be (i) personally served,
(ii) deposited in the mail, registered or certified, return receipt requested,
postage prepaid, (iii) delivered by reputable air courier service with charges
prepaid, or (iv) transmitted by hand delivery, telegram, or facsimile, addressed
as set forth below or to such other address as such Party shall have specified
most recently by written notice. Any notice or other communication required or
permitted to be given hereunder shall be deemed effective (a) upon hand delivery
or delivery by facsimile, with accurate confirmation generated by the
transmitting facsimile machine, at the address or number designated below (if
delivered on a business day during normal business hours where such notice is to
be received), or the first business day following such delivery (if delivered
other than on a business day during normal business hours where such notice is
to be received) or (b) on the second business day following the date of mailing
by reputable courier service, fully prepaid, addressed to such address, or upon
actual receipt of such mailing, whichever shall first occur. The addresses for
such communications shall be:

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<PAGE>

     If to the Company:

          Universal Trading Technologies Corporation
          1900 Market Street, Suite 701
          Philadelphia, PA 19103
          Attn: Fred S. Weingard
          Fax: (215) 636-3560
     If to ATG:

          The Ashton Technology Group, Inc.
          1900 Market Street, Suite 701
          Philadelphia, PA 19103
          Attn: Arthur J. Bacci
          Fax: (215) 636-3560

     with copy to:

          Justin P. Klein, Esquire
          Ballard Spahr Andrews & Ingersoll, LLP
          1735 Market Street
          Philadelphia, PA 19103
          Fax: (215) 864-8999

     If to the Investors:

          TK Holdings, Inc.
          365 Bay Street
          10th Floor
          Toronto, Ontario
          CANADA MSH 2V2
          Attn: Robert Wilson
          Fax: 416-860-8323

          Mark Valentine
          365 Bay Street
          10th Floor
          Toronto, Ontario
          CANADA MSH 2V2
          Fax: 416-860-8323

     with a copy to:

                                       12
<PAGE>

          John Mann, Esquire
          Fax: (713) 622-7114

          Either Party hereto may from time to time change its address or
facsimile number for notices under this Section 9.1 by giving at least ten (10)
days' prior written notice of such changed address or facsimile number to the
other Party hereto.


                                   ARTICLE X
                                 Miscellaneous

          Section X.1  Assignment. Neither this Agreement nor any rights of the
Investors or the Company hereunder may be assigned by either Party to any other
person. Notwithstanding the foregoing, (a) the provisions of this Agreement
shall inure to the benefit of, and be enforceable by, any transferee of any of
the Preferred Stock purchased or acquired by the Investors hereunder with
respect to the Preferred Stock held by such person, and (b) upon the prior
written consent of the Company, which consent shall not unreasonably be
withheld, the Investors's interest in this Agreement may be assigned at any
time, in whole or in part, to any other person or entity (including any
affiliate of the Investors) who agrees to make the representations and
warranties contained in Article II and who agrees to be bound by the covenants
of Article IV.

          Section X.2  Waiver.  No waiver of any terms of this Agreement shall
be valid unless in writing and signed by authorized representatives of each of
the Parties. Failure by any Party to enforce any of its rights under this
Agreement shall not be construed as a waiver of such rights, nor shall a waiver
by any Party in one or more instances be construed as constituting a waiver or
as a waiver in other instances.

          Section X.3  Termination. This Agreement shall terminate 6 years after
the Closing Date.

          Section X.4  Counterparts/Facsimile/Amendments. This Agreement may be
executed in multiple counterparts, each of which may be executed by less than
all of the Parties and shall be deemed to be an original instrument which shall
be enforceable against the Parties actually executing such counterparts and all
of which together shall constitute one and the same instrument. Except as
otherwise stated herein, in lieu of the original documents, a facsimile
transmission or copy of the original documents shall be as effective and
enforceable as the original. This Agreement may be amended only by a writing
executed by all Parties.

          Section X.5  Entire Agreement. This Agreement, the Exhibits or
Attachments hereto set forth the entire agreement and understanding of the
Parties relating to the subject matter hereof and supersedes all prior and
contemporaneous agreements, negotiations and understandings between the Parties,
both oral and written relating to the subject matter hereof.

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<PAGE>

The terms and conditions of all Exhibits and Attachments to this Agreement are
incorporated herein by this reference and shall constitute part of this
Agreement as is fully set forth herein.

          Section X.6  Survival; Severability. The following provisions shall
survive the termination of this Agreement: 2.7, 6.1, 7.2, 8.1, 9.1, 10.6, 10.8,
10.10 and 10.11. In the event that any provision of this Agreement becomes or is
declared by a court of competent jurisdiction to be illegal, unenforceable or
void, this Agreement shall continue in full force and effect without said
provision, provided that such severability shall be ineffective if it materially
changes the economic benefit of this Agreement to any Party.

          Section X.7  Title and Subtitles. The titles and subtitles used in
this Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

          Section X.8  Replacement of Certificates. Upon (i) receipt of evidence
reasonably satisfactory to the Company of the loss, theft, destruction or
mutilation of a certificate representing the Securities and (ii) in the case of
any such loss, theft or destruction of such certificate, upon delivery of an
indemnity agreement or security reasonably satisfactory in form and amount to
the Company or (iii) in the case of any such mutilation, on surrender and
cancellation of such certificate, the Company at its expense will execute and
deliver, in lieu thereof, a new certificate of like tenor to the Investors.

          Section X.9  Fees and Expenses. Each of the Parties shall pay its own
fees and expenses (including the fees of any attorneys, accountants, appraisers
or others engaged by such Party) in connection with this Agreement and the
transactions contemplated hereby.

          Section X.10  Brokerage. Each of the Parties hereto represents that it
has had no dealings in connection with this transaction with any finder or
broker who will demand payment of any fee or commission from the other Party.
The Company on the one hand, and the Investors, on the other hand, agree to
indemnify the other against and hold the other harmless from any and all
liabilities to any person claiming brokerage commissions or finder's fees on
account of services purported to have been rendered on behalf of the
indemnifying Party in connection with this Agreement or the transactions
contemplated hereby.

          Section X.11  Confidentiality. If for any reason the transactions
contemplated by this Agreement are not consummated, each of the Parties hereto
shall keep confidential any information obtained from any other Party (except
information publicly available or in such Party's domain prior to the date
hereof, and except as required by court order) and shall promptly return to the
other Parties all schedules, documents, instruments, work papers or other
written information, without retaining copies thereof, previously furnished by
it as a result of this Agreement or in connection herewith.

                 [Remainder of Page Intentionally Left Blank]

                           [Signature Page Follows]

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<PAGE>

          IN WITNESS WHEREOF, the Parties hereto have caused this Stock Purchase
Agreement to be executed by the undersigned, thereunto duly authorized, as of
the date first set forth above.

Agreed to and Accepted on
this 4th day of June, 1999


                              UNIVERSAL TRADING TECHNOLOGY CORPORATION


                              By:  /s/ Fred S. Weingard
                                 ------------------------
                                       Fred S. Weingard
                                    President


                              TK HOLDINGS, INC.


                              By:  /s/ Robert Wilson
                                 ------------------------
                                       Name:
                                       Title:


                                   /s/ Mark Valentine
                                 ------------------------
                                       MARK VALENTINE


For purposes of Sections 1.3, 1.4, 5.3.2, 5.4, 5.6, 5.9, 5.10, 6.1, 7.1, 8.1,
9.1, 10.2, 10.6, 10.10 and 10.11

THE ASHTON TECHNOLOGY
GROUP, INC.


By: /s/ Arthur J. Bacci
   ------------------------
        Arthur J. Bacci
        President

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