<PAGE>   1
                                                                EXHIBIT 10.12(c)


                              CONSULTING AGREEMENT

         This is a legal agreement ("Agreement"), effective as of the 15th day
of January 2001, executed by and among ORINCON Industries, Inc., a California
corporation having its principal place of business at 9363 Towne Centre Drive,
San Diego, California 92121, ("ORINCON"), John T. Rickard, having an address at
52 Oak View Circle, DWII, Durango, Colorado 81301 ("Dr. Rickard"), and OptiMark,
Inc., a Delaware corporation having its principal place of business at 10
Exchange Place, 24th Floor, Jersey City, New Jersey 07302 ("OptiMark"). ORINCON,
Dr. Rickard, and OptiMark may be referred to herein as the "Parties" and each a
"Party."

         WHEREAS, Dr. Rickard is a Director and Chief Scientific Officer of
OptiMark;

         WHEREAS, Dr. Rickard has been employed by OptiMark or its affiliates
since 1994 and has been primarily responsible for the creation and development
of OptiMark's matching algorithms;

         WHEREAS, Dr. Rickard will leave the employ of OptiMark as of January 5,
2001 and will become employed by ORINCON as of January 15, 2001; and

         WHEREAS, the Parties desire that this Agreement govern and provide the
terms and conditions under which ORINCON shall make Dr. Rickard available to
provide consulting services to OptiMark.

         NOW, THEREFORE, for and in consideration of the agreements set forth
below, the Parties agree as follows:

         1. DESCRIPTION OF WORK. ORINCON agrees to make Dr. Rickard available as
stated herein to provide, and Dr. Rickard agrees to provide, OptiMark with the
services set forth in EXHIBIT A. Dr. Rickard will retain absolute discretion as
to the manner and means of carrying out his activities and responsibilities
hereunder.

         2. PARTIES' RELATIONSHIP. This Agreement does not create an
employee/employer relationship between ORINCON and OptiMark, or Dr. Rickard and
OptiMark. It is the Parties' intention that ORINCON will be an independent
contractor of OptiMark and that ORINCON and Dr. Rickard will not be employees of
OptiMark for any and all purposes, including, without limitation, the
application of the Fair Labor Standards Act minimum wage and overtime
provisions, Federal Insurance Contribution Act, the Social Security Act, the
Federal Unemployment Tax Act, the provisions of the Internal Revenue Code, any
state income tax law, or any local income tax law, any state workers'
compensation laws, and any state unemployment insurance law.

         3. TRAVEL. Upon the reasonable request of OptiMark, Dr. Rickard shall
travel to and from OptiMark, including its Jersey City, NJ office, to perform
certain of the services hereunder; provided, however, that such travel is deemed
reasonably necessary. The Parties agree that Dr. Rickard shall not be obligated
to perform services hereunder outside of Durango, Colorado for more than five
(5) days per calendar quarter.

         4. HOURS. Dr. Rickard shall perform services hereunder for a maximum of
forty five (45) hours per month, which shall include time spent for travel. Dr.
Rickard shall set his own hours and work schedule in coordination with
OptiMark's needs.


                                       1
<PAGE>   2
         5. COMPENSATION. OptiMark will pay ORINCON at the rate(s) specified in
and in accordance with EXHIBIT A. Invoices shall be rendered monthly by ORINCON
on its letterhead and shall specify a brief description of services performed by
Dr. Rickard. OptiMark will pay ORINCON within thirty (30) days of receiving the
invoice. ORINCON represents and warrants that the hourly rate specified in
EXHIBIT A is its normal and customary rate charged for the time of Dr. Rickard.

         6. EXPENSES. OptiMark shall reimburse ORINCON or Dr. Rickard for only
necessary expenses incurred in the rendition of services; provided, however,
that ORINCON and/or Dr. Rickard have obtained prior written approval from
OptiMark before incurring expenses in excess of $250.

         7. SUPPLIES. ORINCON will provide Dr. Rickard with his own supplies and
equipment required to complete the tasks for which he was retained.

         8. TAXES. ORINCON and Dr. Rickard will not be treated as employees with
respect to services rendered under this Agreement for federal, state, and/or
local tax purposes. Neither federal, nor state, nor local income tax, nor
payroll tax of any kind shall be withheld by OptiMark on behalf of ORINCON or
Dr. Rickard. ORINCON and Dr. Rickard understand that it is their responsibility
to pay income, social security, and all other taxes.

         9. BENEFITS. ORINCON and Dr. Rickard acknowledge that they are engaged
in an independent business and are not eligible to participate in any pension,
health, or other fringe benefits plan of OptiMark.

         10. INSURANCE. No Workers' Compensation Insurance shall be obtained by
OptiMark for ORINCON or Dr. Rickard. ORINCON understands that it is its
responsibility to comply with the Workers' Compensation Laws.

         11. CONFIDENTIALITY. Dr. Rickard acknowledges that, during performance
of services under this Agreement, he will have access to information relating to
OptiMark's business that provides OptiMark with a competitive advantage (or that
could be used to OptiMark's disadvantage by a competitor), that is not generally
known by persons not employed/associated with OptiMark and that could not easily
be learned or determined by someone outside OptiMark ("Confidential
Information"). Dr. Rickard acknowledges that Confidential Information shall
include, but not be limited to, all business, technical, proprietary, trade
secret, and other information of OptiMark, its affiliates, or a third party,
whether disclosed in writing, orally, or in any other form, tangible or
intangible, including, but not limited to, patents, patent applications,
research, product plans, product developments, inventions, designs, formulae,
markets, software (including source and object code), algorithms, business
plans, customers, marketing, and finances of OptiMark. Confidential Information
shall not, however, include information that is or becomes widely known to the
general public through no act or failure to act by Dr. Rickard. ORINCON
acknowledges that it shall have access to such Confidential Information by
virtue of Dr. Rickard, its employee, having access to such Confidential
Information.

         12. NONDISCLOSURE AND LIMITED USE. ORINCON and Dr. Rickard agree to use
their best efforts, both during and after performance of services, to hold all
Confidential Information in a fiduciary capacity for the benefit of OptiMark and
to safeguard all such Confidential Information. ORINCON and Dr. Rickard also
agree that they will not directly or indirectly use Confidential Information
except as may be necessary in the good faith performance of services for
OptiMark. Except as permitted under this Agreement, Dr. Rickard shall not
disclose any portion of Confidential Information to any (a) third party or (b)
any other employee, director,


                                       2
<PAGE>   3
officer, or consultant of ORINCON that does not have a need to know. Dr. Rickard
and ORINCON shall immediately notify OptiMark upon receiving a request from a
third party to disclose Confidential Information of OptiMark and shall cooperate
with OptiMark to protect the Confidential Information. The rights set forth
herein are in addition to all rights OptiMark may have under the common law or
the applicable statutory laws relating to the protection of confidential
information and trade secrets.

         13. THIRD PARTY CONFIDENTIAL INFORMATION. ORINCON and Dr. Rickard
recognize that OptiMark has received and in the future may receive from third
parties their confidential or proprietary information subject to a duty on
OptiMark's part to maintain the confidentiality of such information and to use
it only for certain limited purposes. ORINCON and Dr. Rickard agree that they
owe a duty to OptiMark and such third parties, during the term of this Agreement
and thereafter, to hold all such confidential or proprietary information in the
strictest confidence and not to disclose it to any person, firm or corporation
or to use it except as necessary in carrying out the services for OptiMark
consistent with OptiMark's agreement with such third party. ORINCON and Dr.
Rickard shall treat such confidential and/or proprietary information of third
parties (a) as they would treat OptiMark's Confidential Information and/or (b)
pursuant to the terms of agreements governing such information that OptiMark has
with such third parties, if OptiMark informs ORINCON and Dr. Rickard in writing
of the terms of such third party agreements in advance requiring their
compliance with this provision.

         14. NO VIOLATION OF RIGHTS OF THIRD PARTIES. ORINCON and Dr. Rickard
warrant that their performance under the terms of this Agreement does not and
will not breach any of either of their agreements to keep in confidence
proprietary information, knowledge or data acquired by either of them prior to
this engagement. ORINCON and Dr. Rickard warrant that neither is a party to any
other agreement that will interfere with their full compliance with this
Agreement.

         15. NONSOLICITATION. During the term of this Agreement and for a period
of one year thereafter, a party shall not, directly or indirectly, for
themselves or for any other person or entity, attempt to employ or enter into
any contractual arrangement with any current employee or consultant of another.
OptiMark acknowledges and agrees that Dr. Rickard may assist current employees
of OptiMark who are terminated by OptiMark, or who leave OptiMark voluntarily,
in finding other employment; provided, however, that Dr. Rickard and ORINCON do
not violate the first sentence of this Section 15.

         16. INTELLECTUAL PROPERTY AND INVENTIONS. ORINCON and Dr. Rickard
acknowledge that all developments, including, without limitation, the creation
of new products, conferences, training/seminars, publications, methods of
organizing information, inventions, patentable or otherwise, discoveries,
improvements, patents, trademarks, trade names, copyrights, trade secrets,
designs, works, reports, computer software, flow charts and diagrams,
procedures, data, documentation and writings and applications thereof relating
to the business of OptiMark that, alone or jointly with others, ORINCON and Dr.
Rickard may have discovered, conceived, created, made, developed, reduced to
practice or acquired, while performing services under this Agreement
(collectively, "Developments"), are works made for hire and shall remain the
sole and exclusive property of OptiMark. In the case that such Development are
not deemed to be works for hire for any reason, ORINCON and Dr. Rickard hereby
assign to OptiMark all of their right, title and interest in and to all such
Developments. ORINCON and Dr. Rickard agree to disclose to OptiMark promptly and
fully all future Developments and, at any time, either during the term of this
Agreement or thereafter, upon request and at the expense of OptiMark, to
execute, acknowledge and deliver to OptiMark all instruments that OptiMark shall
prepare, to give evidence, and to take any and all other actions that are
necessary or desirable


                                       3
<PAGE>   4
in the reasonable opinion of OptiMark to enable OptiMark to file and prosecute
applications for and to acquire, maintain and enforce all letters patent,
trademark registrations or copyrights covering past or future Developments in
all countries in which the same are deemed necessary by OptiMark. All data,
memoranda, notes, lists, drawings, records, files, customer lists, supplier
lists and other documentation (and all copies thereof) made or compiled by
ORINCON and/or Dr. Rickard or made available to ORINCON or Dr. Rickard
concerning the Developments or otherwise concerning the past, present or planned
business of OptiMark are the property of OptiMark, and will be delivered by
ORINCON and/or Dr. Rickard to OptiMark promptly upon the expiration or
termination of this Agreement. All other discoveries, improvements or inventions
owned by ORINCON and Dr. Rickard at the time of the execution of this Agreement,
are expressly reserved and excepted from the provisions of this Agreement.

         17. COMPANY DOCUMENTS. ORINCON and Dr. Rickard acknowledge that all
documents created by them or received from OptiMark in connection with services
performed are owned by OptiMark or the third party providing them to OptiMark.
Such documents include files, memoranda, correspondence, reports, client lists,
contact lists, clients records and compilations of information, however such
information may be recorded and whether on hard copy or on a computer, computer
disk, or magnetic disk ("Company Documents"). ORINCON and Dr. Rickard agree to
return and/or destroy, at OptiMark's request, all Company Documents (including
all copies) to OptiMark promptly upon completion of services and agrees that,
during and after the term of this Agreement, he will not, under any
circumstances, without the specific written authorization of OptiMark, disclose
Company Documents or any information contained in Company Documents to anyone
outside OptiMark or use Company Documents for any purpose other than the
advancement of OptiMark's interests.

         18. INDEMNITY. ORINCON and Dr. Rickard agree to indemnify and hold
harmless OptiMark, its subsidiaries, affiliates, and their directors, officers,
employees and agents, from and against any and all losses, expenses, costs,
liabilities and damages (including any legal fee and expenses), any and all
injuries, whether direct, consequential or incidental in nature, which result
from, are connected with or arise out of the performance by ORINCON and Dr.
Rickard of the work required under this Agreement, including any act by him
inconsistent with their status as an independent contractor.

         19. TERM. This Agreement shall be effective as of the date first stated
above and shall expire on January 14, 2002 (the "Term"). Notwithstanding the
foregoing, ORINCON shall make Dr. Rickard available to provide the following
service(s) to OptiMark for a period of four (4) years from the termination or
expiration of this Agreement: At any time upon request and at the expense of
OptiMark, Dr. Rickard shall execute, acknowledge and deliver to OptiMark all
instruments that OptiMark shall prepare, to give evidence, and to take any and
all other actions that are necessary or desirable in the reasonable opinion of
OptiMark to enable OptiMark to file, maintain, and prosecute applications for
and to acquire, maintain and enforce, all of OptiMark's letters patent,
trademark registrations, or copyrights in all countries in which the same are
deemed necessary by OptiMark.

         20. ASSIGNMENT. This Agreement may not be assigned or transferred by
ORINCON or Dr. Rickard without the prior written consent of OptiMark. ORINCON
and Dr. Rickard may not subcontract or delegate the services to be performed
hereunder to any third party or any other employee or consultant of ORINCON.

         21. TERMINATION OF RELATIONSHIP. OptiMark may terminate this Agreement
and Exhibit A prior to its expiration for any good cause, as determined in its
reasonable, good faith discretion, upon written notice to ORINCON and Dr.
Rickard. ORINCON and Dr. Rickard may


                                       4
<PAGE>   5
terminate this Agreement if not paid by OptiMark within sixty (60) days after
submission of his invoice.

         22. AMENDMENT. Except upon execution of a new Project List, this
Agreement may only be amended or modified by a writing which makes express
reference to this Agreement as the subject of such amendment and which is signed
by ORINCON and, on behalf of OptiMark, by its duly authorized officer.

         23. SEVERABILITY. If any term, provision, covenant or condition of this
Agreement or part thereof, or the application thereof to any person, place or
circumstance, shall be held to be invalid, unenforceable or void, the remainder
of this Agreement and such term, provision, covenant, or condition shall remain
in full force and effect, and any such invalid, unenforceable or void term,
provision, covenant or condition shall be deemed, without further action on the
part of the parties hereto, modified, amended and limited to the extent
necessary to render the same and the remainder of this Agreement valid,
enforceable and lawful.

         24. ENTIRE AGREEMENT. This Agreement contains the entire agreement and
understanding between the parties hereto in respect to the subject matter hereof
and supersedes, cancels and annuls any prior or contemporaneous written or oral
agreements, understandings, commitments, and practices between them respecting
the subject matter hereof.

         25. GOVERNING LAW. This Agreement shall be governed by and construed in
accordance with the substantive laws, but not the choice of law rules, of the
State of California. Any dispute between the parties related to this Agreement
shall be resolved via final and binding arbitration under the auspices of the
American Arbitration Association, Labor and Employment Section, and the rules
promulgated by that body. The parties hereby agree to share equally the costs of
arbitration so long as each party is solely responsible for his respective
attorneys'/representatives' fees and disbursements. The parties knowingly waive
their right to have a court of law resolve disputes arising under this
Agreement.




                                       5
<PAGE>   6
         26. MISCELLANEOUS. Dr. Rickard agrees that if he should leave the
employ of ORINCON during the Term, or if ORINCON shall be in breach of this
Agreement, then he shall assume all of the rights and obligations of ORINCON
hereunder.


/s/ John. T. Rickard                                 Dated: February 28, 2001
--------------------
John T. Rickard


/s/ R. Taylor                                        Dated: March 5, 2001
-------------
ORINCON, Corporation
(by its duly authorized representative)

/s/ James G. Rickards                                Dated: February 13, 2001
---------------------
OPTIMARK, INC.
(by its duly authorized representative)



                                       6
<PAGE>   7
                                    EXHIBIT A


DESCRIPTION OF PROJECT


         At OptiMark's request(s) from time to time, Dr. Rickard shall (a)
modify, enhance, expand, and consult with OptiMark concerning its existing
technology, research, product plans, product developments, inventions, designs,
formulae, markets, software, algorithms, and functional specifications known to
Dr. Rickard as of January 6, 2001 (collectively, "Technology"), as may be
applied to OptiMark's existing and new clients, exchanges, and markets and (b)
prepare deliverables and/or work product to be specified by OptiMark relating to
the same. For the avoidance of doubt, OptiMark's Technology shall include that
which relates to, negotiation, VWAP, aggregation, and other matching technology
for electronic exchanges and markets.


PERIOD OF PERFORMANCE


         During the Term (as defined in paragraph 19 above).


PROJECT COST/RATE


US$400 per hour plus reasonable, necessary expenses that are covered by policies
adopted by OptiMark, from time to time, for the reimbursement of travel and
entertainment expenses of consultants.

OPTIMARK SUPERVISOR

         [TO BE DETERMINED.]

OTHER

         N/A




                                       7