<PAGE>

                                                                   EXHIBIT 10.17

                        SETTLEMENT, RELEASE, COVENANT NOT
                   TO SUE, WAIVER AND NON-DISCLOSURE AGREEMENT

      WHEREAS, DOUGLAS M. ATKIN, individually and on behalf of all his
successors, heirs, executors, administrators, legal representatives, and assigns
(hereinafter referred to collectively as "Atkin"), and INSTINET GROUP
INCORPORATED, on behalf of its parents, subsidiaries, divisions and affiliates,
and their respective predecessors, successors, assigns, representatives,
officers, directors, shareholders, agents, employees and attorneys (hereinafter
referred to collectively as "Instinet"), have reached agreement with respect to
all matters arising out of Atkin's employment with Instinet and the termination
thereof;

      NOW, THEREFORE, in consideration of the mutual convenants and undertakings
set forth herein, Atkin and Instinet agree as follows:

      1. Termination of Employment. By mutual agreement between the parties,
Atkin's employment with Instinet shall terminate on May 1, 2002 ("Termination
Date"). Through the Termination Date, Instinet will continue to pay Atkin at his
current base salary of $500,000 per annum, with continuation of Instinet's
benefit and fringe programs through such date. Atkin hereby resigns from each of
his employment and director positions with Instinet and its affiliates,
effective as of the Termination Date. Atkin shall execute and deliver such
documents evidencing such resignations as Instinet may reasonably request from
time to time.

      2. Vested Payments and Benefits. Neither Atkin's separation from Instinet
nor this Agreement shall alter or affect in any way Atkin's vested rights, if
any, to payments and benefits pursuant to the Instinet 401(k) Plan, SERP Plan,
Deferred Bonus Plan, or ESPP Plan as of the Termination Date. Atkin shall also
promptly receive payment for any accrued but unused vacation, and reimbursement
for outstanding business expenses.


<PAGE>

      3. Separation Payments and Benefits. Instinet will pay Atkin the amounts
described below, subject to the provisions of this Agreement. The payments to be
provided by Paragraphs 2 and 3 of this Agreement are in place of, and not in
addition to, payments Atkin would otherwise be entitled to pursuant to any
policy or practice of Instinet. All payments made pursuant to this paragraph
will be reduced by any and all applicable payroll deductions including, but not
limited to, federal, state and local tax withholdings.

            (a) Severance Payments. Instinet will pay Atkin severance payments
for a 2-year period (the "Severance Period") at the rate of $500,000 per annum
("Severance Payments") from the Termination Date through May 1, 2004. During the
Severance Period, Atkin will be eligible to continue his current health and
dental coverage for himself and his family as if an active employee, but will
not be eligible for life insurance, long-term disability insurance or any other
benefits. At the end of such period, he shall be entitled to his rights under
COBRA measured from that date. At any time during the Severance Period, Atkin
may elect to have Instinet accelerate the Severance Payments and to receive all
remaining payments in a lump sum. All Instinet payment towards Atkin's health
and dental benefits will terminate, however, upon such lump sum payment and
Atkin's COBRA rights shall commence.

            (b) 2002 Pro Rata Bonus. As a pro rata bonus for calendar year 2002,
Instinet will

                  (i)   pay Atkin $492,918 in February 2003; and

                  (ii)  within ten days of the effectiveness of this Agreement,
                        grant to Atkin 94,000 options under the Instinet 2000
                        Stock Option Plan, such options to have the following
                        terms and conditions:

                        -     term that expires June 1, 2005;


                                                                               2
<PAGE>

                        -     an exercise price equal to the Nasdaq-reported
                              closing sale price on April 30, 2002, regular way,
                              for INET Common Stock; and

                        -     cliff-vesting on February 28, 2003, the only
                              condition of which shall be Atkin's compliance
                              with this Agreement.

            (c) 200% of Average Annual Bonus. Instinet agrees to pay Atkin two
equal installments of $1,375,000 each, the first such installment to be paid in
February 2003 and the second such installment to be paid in May 2003.

            (d) Ex Gratia Payment. Instinet will pay Atkin a one-time ex gratia
payment of $325,000 within ten days of the effectiveness of this Agreement.

            (e) Restricted Stock. Atkin's rights to 32,938 shares of Instinet
restricted stock, which were granted on February 15, 2002 and documented in a
Restricted Stock Unit agreement dated March 20, 2002, will fully vest on
February 15, 2003, provided that Atkin complies with the terms of this
Agreement.

      4. Return of Instinet Property. Except as provided in the next sentence,
Atkin agrees to return to Instinet by no later than the Termination Date, any
and all property (including but not limited to files, records, computer
software, computer access codes, cellular phones, fax machines, company IDs,
business credit cards, proprietary and confidential information) which belongs
to Instinet, and shall not retain any copies, duplicates or excerpts thereof,
provided that Instinet shall make available to Atkin any documents he hereafter
needs to refer to with regard to his service with Instinet as a result of any
third party claims or proceedings. The foregoing sentence notwithstanding, Atkin
may keep his Instinet-provided home computers, printers and related items in New
York, New York and in Sag Harbor, New York at no charge to him.


                                                                               3
<PAGE>

      5. Outplacement Services. At the request of Atkin, Instinet will make
available executive outplacement services to Atkin at a level comparable for his
position, to be provided by a mutually agreeable outplacement firm, for a period
of up to one year.

      6. Instinet Options. Instinet agrees that all options granted by Instinet
to Atkin under the Instinet 2000 Stock Option Plan (including those granted in
2000) will continue to vest during the Severance Period. On the last day of the
Severance Period (May 1, 2004), each outstanding but unvested options shall vest
100% and all options shall remain outstanding until, and expire upon, the 30th
day following the first anniversary of such end of the Severance Period (June 1,
2005). All outstanding options held by Atkin during this period prior to
expiration will be adjusted in the same manner as those outstanding options held
by active employees.

      7. Office and Telephone. Instinet agrees to provide Atkin with use of a
private office with telephone at one of Instinet's facilities in New York, New
York at no cost to Atkin, for the period from his Termination Date through
December 31, 2002.

      8. Full Satisfaction. Atkin, by entering into this Agreement, accepts the
benefits to be conferred on his hereunder in full and complete satisfaction of
any and all asserted and unasserted claims of any kind or description against
Instinet as of the date of this Agreement, including, but not limited to, claims
arising under any federal, state and local fair employment practice law,
workers' compensation law, and any other employee relations statute, executive
order, law and ordinance, including, but not limited to, Title VII of the Civil
Rights Act of 1964, as amended, the Age Discrimination in Employment Act of
1967, as amended, the Rehabilitation Act of 1973, as amended, the Family and
Medical Leave Act, the Americans With Disabilities Act of 1990, as amended, the
Civil Rights Acts of 1866 and 1871, and, except as otherwise expressly set forth
herein, of any other duty and/or other employment related obligation (all of
which are hereinafter referred to as "employment relations laws") as well as any
claims arising


                                                                               4
<PAGE>

from his Employment Agreement with Instinet dated April 2, 2001, tort, tortious
course of conduct, contract, obligations of "good faith," public policy,
statute, common law, equity, and all claims for wages and benefits, monetary and
equitable relief, punitive and compensatory relief, and attorneys' fees and
costs.

      9. Release

      (a) Atkin acknowledges that certain payments provided for in this
Agreement are in excess of the amount that Atkin would otherwise be entitled to
receive and that Instinet has no obligation to enter into this Agreement. In
consideration thereof, Atkin releases and discharges Instinet from any and all
liability, and waives any and all rights of any kind and description that he has
or may have against Instinet as of the date of this Agreement, including, but
not limited to, any asserted and unasserted claims arising from any employment
relations laws, tort, tortious course of conduct, contract (including without
limitation Atkin's Employment Agreement with Instinet dated April 2, 2001),
public policy, statute, common law, and equity, and claims for wages and
benefits, monetary and equitable relief, punitive and compensatory relief, and
attorneys' fees and costs. The foregoing notwithstanding, Atkin's release and
waiver do not apply to: (a) his rights arising out of this Agreement; (b) any
rights that Atkin and any covered dependents may have to purchase health benefit
continuation coverage under federal law commonly known as COBRA; (c) any accrued
benefits which have vested under the terms of the qualified and nonqualified
retirement plans maintained by Instinet as such plans may be amended from time
to time; (d) any rights that Atkin may have to indemnification under Instinet's
general corporate indemnity, Bylaws, certificate of incorporation, plans or
agreements or at law as an officer or director of Instinet and its affiliates or
as a fiduciary of any benefit plan of any of the foregoing; or (e) any rights to
director's and officer's insurance coverage or fiduciary coverage (which
Instinet agrees to continue to cover Atkin under to the same extent it covers
its active officers, directors and fiduciaries).


                                                                               5
<PAGE>

      (b) Instinet releases and discharges Atkin from any and all liability, and
waives any and all rights of any kind and description that it has or may have
against Atkin as of the date of this Agreement, regarding which Instinet has
actual knowledge or should have had knowledge, other than rights under this
Agreement or arising as a result of any criminal act of Atkin.

      10. Non-Competition Covenant. Atkin agrees that he will not, through May
1, 2003, directly or indirectly, engage as officer, employee, agent, partner,
director, consultant or substantial stockholder (i.e., more than 1 percent of
the outstanding common stock) of:

      (a) any of the following companies or their current subsidiaries or
affiliates: Island ECN; MarketXT; Archipelago Holdings L.L.C. - Redi-Book, Terra
Nova or Townsend Analytics, Inc.; LiquidNet; Strike; Ecross Net; Brass Holdings,
Brut ECN or Sungard; Bloomberg; Optimark; ITG; Primex; Cybercorp; Tradescape;
Track ECN; New York Stock Exchange, Inc., the Nasdaq Stock Market, the American
Stock Exchange; or

      (b) any ECN or the US-based electronic trading division or unit of any
financial services firm, provided that the foregoing prohibition shall not
prevent Atkin from working for a financial services firm so long as Atkin is not
working in the ECN or US-based electronic trading division or unit.

      11. Non-Solicitation Covenant. Atkin further agrees that he will not (i)
through May 1, 2003, directly or indirectly solicit (other than through general
solicitation) any employee of Instinet (other than Atkin's former executive
assistant) to leave the employ of Instinet, or (ii) through May 1, 2003,
directly or indirectly initiate contact (other than through general
solicitation) with any client to transact with any other company business in
which Instinet is currently engaged, including but not limited to institutional
equities, clearing and after-hours trading, or to reduce or refrain from doing
any such business with Instinet. The term "client" means any client of Instinet
as of May 1, 2002 with whom Atkin either had material personal


                                                                               6
<PAGE>

contact, or for whom he personally transacted business, and in either case whose
identity became known to him in connection with his relationship with or
employment by Instinet, provided, if any such client ceases to do business with
Instinet, for reasons other than the direct or indirect action of Atkin, such
entity shall no longer be deemed to be a client.

      12. Non-Disparagement. Atkin and Instinet each agree that through June 1,
2005 except, for truthful statements in any proceeding to enforce this Agreement
or pursuant to a valid Subpoena or Court Order or pursuant to regulatory
inquiry, neither will make or publish any statement (orally or in writing) that
reasonably could be expected to become publicly known, or instigate, assist or
participate in the making or publication of any such statement, which would
libel, slander or disparage (whether or not such disparagement legally
constitutes libel or slander) the other or, with respect to Instinet, any of its
affiliates or any other entity or person within Instinet or its affiliates, any
of their affairs or operations, or the reputations of any of their past or
present officers, directors, agents, representatives and employees.

      13. Rights To Intellectual Property. Atkin acknowledges and agrees that
Instinet is the sole and exclusive owner of all right, title and interest in and
to all trademarks, copyrights and all other rights in and to all software,
computer programs, works of authorship, writings (whether or not copyrightable),
inventions (whether or not patentable), discoveries, methods, improvements,
processes, ideas, systems, know-how, data, and any other intellectual creations
of any nature whatsoever that Atkin developed, or assisted in the development
of, in the course of his employment by Instinet (collectively, the "Instinet
Intellectual Property"). All Instinet Intellectual Property is deemed to be
"work made for hire" pursuant to the United States Copyright Act of 1976 (the
"Act") and Instinet thereby owns all right, title and interest in all Instinet
Intellectual Property. To the extent that the Instinet Intellectual Property or
any part thereof is deemed by any court of competent jurisdiction or any
governmental or regulatory agency not to be a "work made for hire" within the
meaning of the Act, the provisions of this


                                                                               7
<PAGE>

section will still control and, for the consideration set forth herein, Atkin
hereby irrevocably and absolutely assigns, sets over and grants to Instinet the
Instinet Intellectual Property and all of his rights therein. Atkin further
agrees to deliver or execute such documents and to do or refrain from doing such
acts as Instinet or its nominee may reasonably request to protect its rights in
the Instinet Intellectual Property.

      14. Consultation and Cooperation By Atkin. Atkin agrees to make himself
reasonably available (with due regard to his other commitments) to Instinet
during the Severance Period to respond to requests by Instinet for information
concerning facts or events relating to Instinet during his employment period
that may be within his knowledge. Atkin will reasonably cooperate with Instinet
(with due regard to his other commitments) in connection with any or all future
litigation or regulatory proceedings brought by or against Instinet involving
events during his employment period to the extent Instinet reasonably deems
Atkin's cooperation either necessary or helpful. In the event that Instinet
requires Atkin's cooperation, Instinet agrees to pay any of Atkin's reasonable
expenses in providing such cooperation (such as travel and accommodations).

      15. Reemployment or Reinstatement. Atkin agrees not to seek reinstatement
or reemployment with Instinet, and hereby waives any rights that may accrue to
him from any rejection of any application for employment with Instinet that he
may make.

      16. No Admission of Liability. By entering into this Agreement, the
parties do not admit to any liability, wrongdoing, breach of any contract,
commission of any tort or the violation of any statute or law alleged by the
other to have been violated or otherwise.

      17. Entire Agreement and Severability. This Agreement constitutes the
complete settlement of all issues and disputes existing between Atkin and
Instinet as of the date hereof, and may not be modified except by a suitable
writing signed by both Atkin and Instinet. This


                                                                               8
<PAGE>

Agreement has been entered into by Atkin and Instinet voluntarily, knowingly,
and upon advice of counsel. If any provision of this Agreement is held to be
invalid, the remaining provisions shall remain in full force and effect.
Sections 7 through 14 of the Employment Agreement shall be of no further force
or effect.

      18. Injunctive Relief. Atkin acknowledges that a violation on Atkin's part
of this Agreement, including in particular violation of the provisions of
paragraphs 10, 11, and 12 would cause irreparable damage to Instinet.
Accordingly, Atkin agrees that Instinet is entitled to injunctive relief from
any court of competent jurisdiction for any actual or threatened violation of
this Agreement in addition to any other remedies it may have.

      19. Challenge to Release. Atkin agrees that, without limiting Instinet's
remedies, should he commence, continue, join in, or in any other manner attempt
to assert through litigation or proceeding (a "Release Challenge") any claim
released in connection herewith (provided if a class action is involved, Atkin's
obligation is to opt out when given the opportunity), Instinet shall not be
required to make any further payments to Atkin pursuant to this Agreement and
that Instinet shall be entitled to recover all payments already made by it
(including interest thereon) pursuant to paragraph 3 hereof, in addition to all
damages, attorney's fees and costs, Instinet incurs in connection with the
Atkin's Release Challenge. Atkin further agrees that Instinet shall be entitled
to the repayments and recovery of damages described above, in connection with
such Release Challenge, without waiver of or prejudice to the release granted by
him in connection with this Agreement

      20. Attorney Fees. The parties agree that, in any suit brought by either
party for breach of this Agreement by the other, the non-prevailing party will
be liable for the reasonable attorneys fees of the prevailing party in those
circumstances where the non-prevailing party is found to have acted frivolously
or in bad faith.


                                                                               9
<PAGE>

      21. Execution.

            a. Atkin acknowledges that he has had more than twenty-one (21) days
from his receipt of this document to review it. Upon execution, Atkin or his
attorney must promptly send this document by overnight mail to the General
Counsel at Instinet. A copy may be retained by Atkin.

            b. Following his signing of the Agreement, Atkin has the right to
revoke the Agreement at any time within seven (7) calendar days of his signing
it, not including the date of his signing (the "Revocation Period"). Notice of
Revocation shall be given in writing and sent by overnight mail no later than
the seventh day following the date Atkin signs this Agreement to General
Counsel, Instinet Corporation, 3 Times Square, New York, NY 10036. If Atkin does
not revoke the Agreement, this Agreement shall be deemed to be effective and to
be enforceable as of the last date set forth opposite any signature hereto. If
Atkin gives Notice of Revocation during the Revocation Period in the manner
specified above, this Agreement shall become null and void and all rights and
claims of the parties which would have existed, but for the execution of this
Agreement shall be restored.

      22. Governing Law; Venue. This Agreement shall be governed by and
construed in accordance with the law of the State of New York. Section 17(b) of
the Employment Agreement shall apply to any dispute hereunder, subject to
paragraph 20 above.


                                                                              10
<PAGE>


      23. Successors and Assigns. This Agreement shall be binding upon and shall
inure to the benefit of the heirs, successors and assigns of the parties hereto.

      THE UNDERSIGNED, intending to be legally bound, have executed this
Agreement on this 30th day of April, 2002.


DOUGLAS M. ATKIN                            INSTINET GROUP INCORPORATED


/s/ Douglas M. Atkin                        By: /s/ Andre F.H. Villeneuve
-----------------------------                   --------------------------------
                                                Andre F.H. Villeneuve
                                                Chairman

STATEMENT BY THE EMPLOYEE WHO IS SIGNING BELOW: INSTINET HAS ADVISED ME IN
WRITING TO CONSULT WITH AN ATTORNEY PRIOR TO EXECUTING THIS RELEASE. I HAVE
CAREFULLY READ AND FULLY UNDERSTAND THE PROVISIONS OF THIS RELEASE AND HAVE HAD
SUFFICIENT TIME AND OPPORTUNITY (OVER A PERIOD OF AT LEAST 21 DAYS) TO CONSULT
WITH MY PERSONAL TAX, FINANCIAL AND LEGAL ADVISORS PRIOR TO EXECUTING THIS
DOCUMENT, AND I INTEND TO BE LEGALLY BOUND BY ITS TERMS. I UNDERSTAND THAT I MAY
REVOKE THIS RELEASE WITHIN SEVEN (7) DAYS FOLLOWING MY SIGNING, AND THIS RELEASE
WILL NOT BECOME ENFORCEABLE OR EFFECTIVE UNTIL THAT SEVEN (7) DAY PERIOD HAS
EXPIRED.

                                                    DOUGLAS M. ATKIN


                                            Signed: /s/ Douglas M. Atkin
                                                    ----------------------------

THIS IS A RELEASE. READ CAREFULLY BEFORE SIGNING.


                                                                              11