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                                                                    EXHIBIT 10.9

                                    GUARANTY

          GUARANTY dated as of February 20, 2000 by EWDB North America, Inc., a
Delaware corporation (the "Guarantor") and wholly-owned subsidiary of Havas
Advertising ("Parent"), in favor of Snyder Communications, Inc. (the "Guarantied
Party").

                             W I T N E S S E T H:

          WHEREAS, pursuant to the Agreement and Plan of Merger dated as of
February 20, 2000 (as the same may be amended, restated, supplemented or
otherwise modified from time to time, the "Merger Agreement"; capitalized terms
defined therein and used herein having the meanings given to them in the Merger
Agreement) among Parent, HAS Acquisition Corp. (the "Merger Subsidiary") and the
Guarantied Party whereby Merger Subsidiary shall be merged with and into the
Guarantied Party (the "Merger"), Parent has agreed to pay to the Guarantied
Party the sum of $85,000,000 in the event the Merger Agreement is terminated
under certain circumstances as provided in Article 7 thereof; and

          WHEREAS, the Guarantor is an indirect wholly owned subsidiary of
Parent; and

          WHEREAS, the Guarantor will receive substantial direct and indirect
benefits from the Merger Agreement; and

          WHEREAS, it is a condition to the Merger Agreement that the Guarantor
execute and deliver this Guaranty for the benefit of the Guarantied Party;

          NOW, THEREFORE, in consideration of the premises set forth above, the
terms and conditions contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto hereby agree as follows:

          Section 1.  Guaranty.
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          (a)  To induce the Guarantied Party to enter into the Merger
Agreement, the Guarantor hereby absolutely, unconditionally and irrevocably
guarantees, as primary obligor and not merely as surety, the full and punctual
payment, if any, when due of the obligations of Parent under Section 7.03 of the
Merger Agreement (the "Obligations"), whether or not from time to time reduced
or extinguished or hereafter increased or incurred, whether or not recovery may
be or hereafter may become barred by any statute of limitations, and whether
enforceable
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or unenforceable as against the Parent, now or hereafter existing, including the
amount of such payment and all fees and costs of collection. This Guaranty
constitutes a guaranty of payment and not of collection.

          (b)  The Guarantor further agrees that, if any payment made by Parent
or any other person and applied to the obligations is at any time annulled,
avoided, set aside, rescinded, invalidated, declared to be fraudulent or
preferential or otherwise required to be refunded or repaid, the Guarantor's
liability hereunder shall be and remain in full force and effect, as fully as if
such payment had never been made or, if prior thereto this Guaranty shall have
been cancelled or surrendered, this Guaranty shall be reinstated in full force
and effect, and such prior cancellation or surrender shall not diminish,
release, discharge, impair or otherwise affect the obligations of the Guarantor
in respect of the amount of such payment.

          Section 2.  Limitation of Guaranty. Any term or provision of this
                      ----------------------
Guaranty to the contrary notwithstanding, the maximum aggregate amount of the
Obligations for which the Guarantor shall be liable shall not exceed the maximum
amount for which the Guarantor can be liable without rendering this Guaranty
subject to avoidance under applicable law relating to fraudulent conveyance or
fraudulent transfer (including section 548 of the Bankruptcy Code or any
applicable provisions of comparable state law) (collectively, "Fraudulent
Transfer Laws"), in each case after giving effect (a) to all other liabilities
of the Guarantor, contingent or otherwise, that are relevant under such
Fraudulent Transfer Laws (specifically excluding, however, any liabilities of
the Gaurantor in respect of intercompany indebtedness to Parent to the extent
that such indebtedness would be discharged in an amount equal to the amount paid
by the Guarantor hereunder) and (b) to the value as assets of the Guarantor (as
determined under the applicable provisions of such Fraudulent Transfer Laws) of
any rights to subrogation, contribution, reimbursement, indemnity or similar
rights held by the Guarantor pursuant to (i) applicable law or (ii) any other
agreement providing for an equitable allocation among the Guarantor and other
subsidiaries or affiliates of Parent of obligations arising under this Guaranty.

          Section 3.  Authorization; Other Agreements. The Guaranteed Party is
                      -------------------------------
hereby authorized, without notice to or demand upon the Guarantor, which notice
or demand is expressly waived hereby, and without discharging or otherwise
affecting the obligations of the Guarantor hereunder (which shall remain
absolute and unconditional notwithstanding any such action or omission to act),
from time to time, to:

          (a)  supplement, renew, extend, accelerate or otherwise change the
time for payment of, or other terms relating to, the Obligations, or any part to
them, or otherwise modify, amend or change the terms of the Merger Agreement;

                                       2
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          (b)  waive or otherwise consent to noncompliance with any provision of
any instrument evidencing the Obligations, or any part thereof, or any other
instrument or agreement in respect of the Obligations (including the Merger
Agreement) now or hereafter executed by Parent and delivered to the Guarantied
Party or any of them;

          (c)  accept partial payments on the Obligations;

          (d)  receive, take and hold security or collateral for the payment of
the Obligations or any part of them and exchange, enforce, waive, substitute,
liquidate, terminate, abandon, fail to perfect, subordinate, transfer, otherwise
alter and release any such additional security or collateral;

          (e)  settle, release, compromise, collect or otherwise liquidate the
Obligations or accept, substitute, release, exchange or otherwise alter, affect
or impair any security or collateral for the Obligations or any part of them or
any other guaranty therefor, in any manner;

          (f)  add, release or substitute any one or more other guarantors,
makers or endorsers of the Obligations or any part of them and otherwise deal
with Parent or any other guarantor, maker or endorser; or

          (g)  refund at any time any payment received by the Guarantied Party
in respect of any of the Obligations, and payment to the Guarantied Party of the
amount so refunded shall be fully guaranteed hereby even though prior thereto
this Guaranty shall have been cancelled or surrendered, and such prior
cancellation or surrender shall not diminish, release, discharge, impair or
otherwise affect the obligations of the Guarantor hereunder in respect of the
amount so refunded;

even if any right of reimbursement or subrogation or other right or remedy of
the Guarantor is extinguished, affected or impaired by any of the foregoing
(including, without limitation, any election of remedies by reason of any
judicial, non-judicial or other proceeding in respect of the Obligations which
impairs any subrogation, reimbursement or other right of the Guarantor).

          Section 4.  Guaranty Absolute and Unconditional. The Guarantor hereby
                      -----------------------------------
agrees that its obligations under this Guaranty are absolute and unconditional
and shall not be discharged or otherwise affected as a result of:

          (a)  the invalidity or unenforceability of any Parent's obligations
under the Merger Agreement or any other agreement or instrument relating
thereto, or any security for, or other guaranty of the Obligations or any part
of them, or the lack of perfection or continuing perfection or failure of
priority of any security for the Obligations or any part of them;
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          (b)  the absence of any attempt to collect the Obligations or any part
of them from Parent or other action to enforce the same;

          (c)  failure by the Guarantied Party to take any steps to perfect and
maintain any lien on, or to preserve any rights to, any collateral;

          (d)  the Guarantied Party's election, in any proceeding instituted
under chapter 11 of the Bankruptcy Code, of the application of Section
1111(b)(2) of the Bankruptcy Code;

          (e)  any borrowing or grant of a lien by Parent, as debtor-in-
possession, or extension of credit, under Section 364 of the Bankruptcy Code;

          (f)  the disallowance, under Section 502 of the Bankruptcy Code, of
all or any portion of the Guarantied Party's claim (or claims) for repayment of
the Obligations;

          (g)  any use of cash collateral under Section 363 of the Bankruptcy
Code;

          (h)  any agreement or stipulation as to the provision of adequate
protection in any bankruptcy proceeding;

          (i)  the avoidance of any lien in favor of the Guarantied Party or any
of them for any reason;

          (j)  any bankruptcy, insolvency, reorganization, arrangement,
readjustment of debt, liquidation or dissolution proceeding commenced by or
against Parent, the Guarantor or any of the Parent's other subsidiaries,
including without limitation, any discharge of, or bar or stay against
collecting, all or any of the Obligations (or any part of them or interest
thereon) in or as a result of any such proceeding;

          (k)  failure by the Guarantied Party to file or enforce a claim
against Parent or its estate in any bankruptcy or insolvency case or proceeding;
or

          (l)  any action taken by the Guarantied Party that is authorized
hereby;

          (m)  any other circumstance which might otherwise constitute a legal
or equitable discharge or defense of a surety or guarantor or any other obligor
on any obligations, other than the payment in full of the Obligations.

          Section 5.  Waivers. The Guarantor hereby waives diligence,
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promptness, presentment, demand for payment or performance and protest and
notice of protest, notice of acceptance and any other notice in respect of the
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Obligations or any part of them, and any defense arising by reason of any
disability or other defense of Parent. The Guarantor shall not, until the
Obligations are irrevocably paid in full and the Merger Agreement has been
terminated, assert any claim or counterclaim it may have against Parent or set
off any of its obligations to Parent against any obligations of Parent to it. In
connection with the foregoing, the Guarantor covenants that its obligations
hereunder shall not be discharged, except by complete performance.

          Section 6.  Reliance. The Guarantor hereby assumes responsibility for
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keeping itself informed of the financial condition of Parent and any and all
endorsers and/or other guarantors of all or any part of the Obligations, and of
all other circumstances bearing upon the risk of nonpayment of the Obligations,
or any part thereof, that diligent inquiry would reveal, and the Guarantor
hereby agrees that the Guarantied Party shall have no duty to advise the
Guarantor of information known to it regarding such condition or any such
circumstances.

          Section 7.  Waiver of Subrogation and Contribution Rights. Until the
                      ---------------------------------------------
Obligations have been irrevocably paid in full and the Merger Agreement has been
terminated, the Guarantor shall not enforce or otherwise exercise any right of
subrogation to any of the rights of the Guarantied Parties or any part of them
against the Parent or any right of reimbursement or contribution or similar
right against Parent by reason of this Agreement or by any payment made by the
Guarantor in respect of the Obligations.

          Section 8.  Irrevocability. This Guaranty shall be irrevocable as to
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any and all of the Obligations until the Merger Agreement has been terminated
and all monetary Obligations then outstanding have been irrevocably repaid in
cash, at which time this Guaranty shall automatically be cancelled.

          Section 9.  Enforcement; Amendments; Waivers. No delay on the part of
                      --------------------------------
the Guarantied Party in the exercise of any right or remedy arising under this
Guaranty, the Merger Agreement or otherwise with respect to all or any part of
the Obligations, or any other guaranty of or security for all or any part of the
Obligations shall operate as a waiver thereof, and no single or partial exercise
by any such person of any such right or remedy shall preclude any further
exercise thereof. No modification or waiver of any of the provisions of this
Guaranty shall be binding upon the Guarantied Party, except as expressly set
forth in a writing duly signed and delivered by the party making such
modification or waiver. Failure by the Guarantied Party at any time or times
hereafter to require strict performance by Parent, the Guarantor, any other
guarantor of all or any part of the Obligations or any other person of any of
the provisions, warranties, terms and conditions contained in the Merger
Agreement now or at any time or times hereafter executed by such Persons and
delivered to the Guarantied Party shall not waive, affect or diminish any right
of the Guarantied Party at any time or times hereafter to
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demand strict performance thereof and such right shall not be deemed to have
been waived by any act or knowledge of the Guarantied Party, or its respective
agents, officers or employees, unless such waiver is contained in an instrument
in writing, directed and delivered to Parent or the Guarantor, as applicable,
specifying such waiver, and is signed by the party or parties necessary to give
such waiver under the Merger Agreement. Any determination by a court of
competent jurisdiction of the amount owing by Parent to a Guarantied Party shall
be conclusive and binding on the Guarantor irrespective of whether the Guarantor
was a party to the suit or action in which such determination was made.

          Section 10.   Successors and Assigns. This Guaranty shall be binding
                        ----------------------
upon the Guarantor and upon the successors and assigns of the Guarantor and
shall inure to the benefit of the Guarantied Party and its respective successors
and assigns; all references herein to Parent and to the Guarantor shall be
deemed to include their respective successors and assigns. The successors and
assigns of the Guarantor and Parent shall include, without limitation, their
respective receivers, trustees and debtors-in-possession. All references to the
singular shall be deemed to include the plural where the context so requires.

          Section 11.   Governing Law. This Guaranty and the rights and
                        -------------
obligations of the parties hereto shall be governed by, and construed and
interpreted in accordance with, the law of the State of New York.

          Section 12.   Jurisdiction; Service of Process.
                        --------------------------------

          (a)  Any legal action or proceeding with respect to this Guaranty, may
be brought in the courts of the State of New York or of the United States of
America for the Southern District of New York, and, by execution and delivery of
this Agreement, the Guarantor hereby accepts for itself and in respect of its
property, generally and unconditionally, the jurisdiction of the aforesaid
courts. The parties hereto hereby irrevocably waive any objection, including any
objection to the laying of venue or based on the grounds of forum non
conveniens, which any of them may now or hereafter have to the bringing of any
such action or proceeding in such respective jurisdictions.

          (b)  The Guarantor hereby irrevocably consents to the service of any
and all legal process, summons, notices and documents in any suit, action or
proceeding brought in the United States of America arising out of or in
connection with this Guaranty by the mailing (by registered or certified mail,
postage prepaid) or delivering of a copy of such process to the Guarantor care
of Parent at the Parent's address specified in the Merger Agreement. The
Guarantor agrees that a final judgment in any such action or proceeding shall be
conclusive and may be enforced in other jurisdictions by suit on the judgment or
in any other manner provided by law.
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          (c)  Nothing contained in this Section 12 shall affect the right of
the Guarantied Party to serve process in any other manner permitted by law or
commence legal proceedings or otherwise proceed against the Guarantor in any
other jurisdiction.

          Section 13. Waiver of Jury Trial. Each of the Guarantied Party and the
                      --------------------
Guarantor irrevocably waives trial by jury in any action or proceeding with
respect to this Guaranty.

          Section 14. Notices. Any notice or other communication herein required
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or permitted shall be given as provided in the Merger Agreement and, in the case
of the Guarantor, to the Guarantor in care of Parent.

          Section 15. Severability. Wherever possible, each provision of this
                      ------------
Guaranty shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Guaranty shall be prohibited by or
invalid under such law, such provision shall be ineffective to the extent of
such prohibition or invalidity without invalidating the remainder of such
provision or the remaining provisions of this Guaranty.

          Section 16. Costs and Expenses. The Guarantor agrees to pay or
                      ------------------
reimburse the Guarantied Party upon demand for all out-of-pocket costs and
expenses, including, without limitation, reasonable attorneys' fees (including
costs of settlement), incurred by the Guarantied Party in enforcing this
Guaranty or any security therefor or exercising or enforcing any other right or
remedy available in connection herewith or therewith.

          Section 17. Waiver. The Guarantor hereby irrevocably and
                      ------
unconditionally waives, to the maximum extent not prohibited by law, any right
it may have to claim or recover any special, exemplary, punitive or
consequential damage in any legal action or proceeding in respect of this
Guaranty.

          Section 18. Entire Agreement. This Guaranty represents the entire
                      ----------------
agreement and understanding of the parties hereto and supersedes all prior
understandings, written and oral, relating to the subject matter hereof.



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          IN WITNESS WHEREOF, this Guaranty has been duly executed by the
Guarantor as of the day and year first set forth above.


                                        EWDB NORTH AMERICA, INC.

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

Acknowledged and agreed to
as of the date first above written:

SNYDER COMMUNICATIONS, INC.

By: /s/ A. Clayton Perfall
    -------------------------
    Name:  C. Perfall
    Title: CFO

                          Signature Page to Guaranty