CONFORMED COPY

                               DATED 22 June 1998

                               OMNICOM GROUP INC.

                                     - and -

                               MORGAN STANLEY S.A.

                                   and Others

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

                             SUBSCRIPTION AGREEMENT

                                   relating to
                                FRF 1,000,000,000
                          5.20 per cent. Notes due 2005

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

                                 Clifford Chance
                                     London



Reference              Description                  Procedures and Findings
- ---------              -----------                  -----------------------

The Issuer's           Total capitalisation         We added total long-term
Capitalisation,        at March 31, 1998            debt and total shareholders'
page 18                and March 31, 1997.          equity, noting agreement
                                                    with total capitalisation at
                                                    March 31, 1998 and
                                                    March 31, 1997



THIS AGREEMENT is made on 22 June 1998

BETWEEN:

(1)   OMNICOM GROUP INC. (the "Issuer"); and

(2)   MORGAN   STANLEY  S.A.   ("MSSA"),   SOCIETE   GENERALE,   DRESDNER   BANK
      AKTIENGESELLSCHAFT,  BANQUE NATIONALE DE PARIS,  PARIBAS,  CREDIT AGRICOLE
      INDOSUEZ,  CREDIT  COMMERCIAL DE FRANCE and NATEXIS BANQUE  (together with
      MSSA, the "Managers").

The Issuer and the Managers wish to record the arrangements  agreed between them
in relation to an issue of FRF  1,000,000,000  5.20 per cent.  Notes due 2005 of
the Issuer (the  "Notes",  which  expression  where the context so admits  shall
include the Temporary Global Note (the "Temporary  Global Note") to be delivered
in respect of them and the Permanent  Global Note (the "Permanent  Global Note")
for  which  interests  in the  Temporary  Global  Note  are  exchangeable).  The
Permanent  Global Note will,  in turn, be  exchangeable  for Notes in definitive
form ("Definitive  Notes") with interest coupons  ("Coupons")  attached,  in the
circumstances  specified  in the  Permanent  Global  Note.  The Notes will be in
bearer form in the denominations of FRF 10,000 and FRF 100,000 each.

1. ISSUE OF THE NOTES AND PUBLICITY

(A)   Agreement to Issue

The Issuer agrees to issue the Notes to the Managers or as they may direct on 24
June 1998 or such later date,  not being later than 10 July 1998,  as the Issuer
and MSSA on behalf of the Managers  may agree (the  "Closing  Date").  The Notes
will be subscribed at a price equal to 99.822 per cent. of the principal  amount
of the Notes (the "Issue  Price") less the  commissions,  concessions  and other
amounts  which the Issuer has  authorised  to be  deducted  from the Issue Price
hereunder   (the  "Selling   Price").   References  in  this  Agreement  to  the
"Pre-Closing Date" are to the last day preceding the Closing Date on which banks
are open for business and on which  dealings in foreign  currency may be carried
on in London.

(B)   The Notes

The Issuer will,  not later than the Closing Date,  enter into (and provide MSSA
with a copy of):

      (1)   a fiscal  agency  agreement  (the "Fiscal  Agency  Agreement")  with
            Societe  Generale Bank & Trust S.A.,  Luxembourg as fiscal agent and
            the other paying agent referred to in it; and

      (2)   a deed of covenant (the "Deed of Covenant")  each  substantially  in
            the form of the draft signed for  identification  by Clifford Chance
            and Dewey  Ballantine  LLP with such  changes as may be  approved by
            MSSA.  The Fiscal  Agency  Agreement  and the Deed of  Covenant  are
            together referred to as the "Contracts".


                                      -1-


(C)   Offering Circular

The Issuer confirms that it has prepared an offering circular dated 22 June 1998
(the  "Offering  Circular"),  which  expression  shall  include any amendment or
supplement  prepared  pursuant to Clause  7(C)) for use in  connection  with the
issue of the Notes and hereby  authorises  the Managers to distribute  copies of
it, in accordance with the restrictions set forth in Schedule I attached hereto,
copies of it in preliminary or draft form having already been  distributed  with
the consent of the Issuer.

(D)   Publicity

The  Issuer  confirms  the   arrangements   made  on  its  behalf  by  MSSA  for
announcements  in respect of the Notes to be published on such dates and in such
newspapers or other  publications  as it may agree with MSSA. It is acknowledged
by MSSA that  announcements  in respect of the Notes will be published only with
the  Issuer's  prior  agreement  on  matters  of form,  substance  and places of
publication.

2.    STABILISATION

MSSA may, to the extent  permitted  by  applicable  laws,  over-allot  or effect
transactions in any over-the-counter  market or otherwise in connection with the
distribution  of the Notes with a view to stabilising or maintaining  the market
price of the Notes at levels other than those which might  otherwise  prevail in
the open market but in doing so MSSA shall act as principal  and not as agent of
the Issuer and any loss resulting from  over-allotment or stabilisation  will be
borne,  and any  profit  arising  from them  shall be  retained,  by MSSA.  Such
stabilising shall be conducted in accordance with all applicable laws and rules.
MSSA acknowledges that the Issuer has not authorised, and shall not be obligated
to   undertake,   the   issue  of  Notes  in  a   principal   amount   exceeding
FRF 1,000,000,000.

3.    AGREEMENTS BY THE MANAGERS

(A)   Subscription

The Managers  jointly and severally  agree to subscribe and pay for the Notes at
the Selling Price on the Closing Date on the terms of this Agreement.

(B)   Restrictions

Each Manager represents,  warrants and agrees in the terms set out in Schedule I
attached hereto.

(C)   Managers' Indemnity

Each Manager agrees to indemnify the Issuer and each of its directors,  officers
and  employees,  against any loss,  liability,  cost,  expense,  claim or action
(including  all  reasonable  costs,  charges or  expenses  paid or  incurred  in
disputing  or  defending  any of the  foregoing)  which any of them may incur or
which may be made  against  any of them  arising  out of, in  relation  to or in
connection with, any failure by such Manager to observe the terms and provisions
set out in Schedule I hereto

4.    LISTING

(A)   Application for Listing

The Issuer confirms that it has authorised MSSA to make, or cause to be made, an
application  on its behalf for the Notes to be listed on the Paris  Bourse  (the
"Stock Exchange").


                                      -2-


(B)   Supply of Information

The Issuer agrees to deliver to MSSA for delivery to the Stock  Exchange  copies
of the Offering Circular and to take such other steps as may be required for the
purpose of obtaining such listing.

(C)   Maintenance of Listing

The  Issuer  will use all  reasonable  endeavours  to obtain and  maintain  such
listing for as long as any Note is outstanding.  If, however, it is unable to do
so, having used such endeavours, or if the maintenance of such listing is unduly
onerous,  the Issuer will instead use all  reasonable  endeavours  to obtain and
maintain a listing  for the Notes on such other  stock  exchange as it may (with
the approval of MSSA) decide.

5.    REPRESENTATIONS AND WARRANTIES

The Issuer represents and warrants to the Managers and each of them that:

(1)  Incorporation:  it is duly incorporated and validly existing under the laws
of the State of New York, with full corporate power and authority to conduct its
business as described in the Offering Circular;

(2) Capacity:  it has full corporate  power and capacity to create and issue the
Notes,  to execute this Agreement and the Contracts and to undertake and perform
the obligations expressed to be assumed by it herein and therein, and the Issuer
has taken all necessary action to approve and authorise the same;

(3) Validity of Contracts: this Agreement has been duly authorised, executed and
delivered  by the  Issuer  and  constitutes,  and the  Contracts  have been duly
authorised  by the Issuer and on the  Closing  Date,  upon their  execution  and
delivery by the Issuer, will constitute,  valid, legally binding and enforceable
obligations of the Issuer;

(4) Validity of Notes:  the Notes have been duly  authorised  by the Issuer and,
when duly executed,  authenticated,  issued and delivered in accordance with the
Fiscal Agency Agreement,  will constitute valid, legally binding and enforceable
obligations of the Issuer;

(5)  Status:  the  Notes  will  constitute  direct,  general  and  unconditional
obligations  of the Issuer which (i) rank pari passu among  themselves  and (ii)
(subject to Condition 3 of the Notes) will at all times rank at least pari passu
with all other present and future unsecured  obligations of the Issuer, save for
such  obligations  as may be  preferred  by  provisions  of law  that  are  both
mandatory and of general application;

(6)  Consents:  no action or thing is  required to be taken,  fulfilled  or done
(including,  without limitation,  the obtaining of any consent or licence or the
making of any filing or  registration)  for or in connection  with the execution
and delivery of this  Agreement and the Contracts,  the issue of the Notes,  the
carrying out of the transactions  contemplated  therein or the compliance by the
Issuer  with the terms of the Notes and the  Contracts,  except for those  which
have been, or will on or prior to the Closing Date be, obtained and are, or will
on the Closing Date be, in full force and effect;


                                      -3-


(7) Compliance:  the execution and delivery of this Agreement and the Contracts,
the  issue of the  Notes,  the  carrying  out of the  transactions  contemplated
therein and  compliance  with the terms thereof do not and will not (a) conflict
with or result in a breach of any of the terms or provisions of, or constitute a
default  under,  the  articles  of  incorporation,  charter,  by-laws  (or other
constitutive documents) of the Issuer or any indenture,  trust deed, mortgage or
other agreement or instrument to which the Issuer or any of its  subsidiaries is
a party or by which any of them or any of their respective  properties is bound,
or (b) infringe any existing applicable law, rule, regulation,  judgment,  order
or decree of any  government,  governmental  body or court or  regulatory  body,
domestic or foreign, having jurisdiction over the Issuer, any such subsidiary or
any of their respective properties;

(8) Offering Circular: the Offering Circular, as of the date hereof, is accurate
in all material respects and does not contain any untrue statement of a material
fact or omit to  state  any  material  fact  necessary  to make  the  statements
therein,  in the light of the  circumstances  under  which they were  made,  not
misleading,  and the Offering Circular will be, as of the Closing Date, accurate
in all material respects and will not contain any untrue statement of a material
fact or omit to  state  any  material  fact  necessary  to make  the  statements
therein,  in the light of the  circumstances  existing at the Closing Date,  not
misleading,  provided that the Issuer makes no  representation or warranty as to
statements  or  omissions  from the list of  Managers  on the cover  page of the
Offering  Circular or under the caption  "Subscription and Sale" in the Offering
Circular,  which  statements were made in reliance upon, and in conformity with,
information  furnished in writing to the Issuer by the Managers specifically for
inclusion therein;

(9)  Financial  Statements:  (a) the  consolidated  financial  statements of the
Issuer  and its  consolidated  subsidiaries  taken as whole  (the  "Consolidated
Group")  for the  years  ended 31  December  1996 and 31  December  1997 and the
consolidated  financial statements of the Consolidated Group for the three month
period ended 31 March 1998 in each case appearing in the Offering  Circular were
prepared in accordance with  accounting  principles  generally  accepted in, and
pursuant  to the  relevant  laws of, the United  States of America  consistently
applied  (except as otherwise  disclosed in the Offering  Circular)  and present
fairly the financial position of the Consolidated Group as at the dates, and the
results of  operations  and changes in  financial  position of the  Consolidated
Group for the periods, in respect of which they have been prepared and (b) since
31  December  1997  there  has  been no  change,  nor any  development  or event
involving a  prospective  change of which the Issuer is, or might  reasonably be
expected to be, aware which is materially adverse to the condition (financial or
other),  results  of  operations  or  general  affairs  of the  Issuer or of the
Consolidated Group;

(10) Litigation:  there are no pending actions,  suits or proceedings against or
affecting  the  Issuer,  any of its  subsidiaries  or  any of  their  respective
properties which, if determined  adversely to the Issuer or any such subsidiary,
could  individually  or in the aggregate have an adverse effect on the condition
(financial or other),  results of operations or general affairs of the Issuer or
the Consolidated  Group or would materially  adversely affect the ability of the
Issuer to perform its  obligations  under this  Agreement,  the Contracts or the
Notes or which are  otherwise  material in the context of the issue of the Notes
and,  to the  best  of  the  Issuer's  knowledge,  no  such  actions,  suits  or
proceedings are threatened or contemplated;


                                      -4-


(11) Events of Default:  no event has occurred or circumstance arisen which, had
the Notes already been issued,  might  (whether or not with the giving of notice
and/or the  passage  of time  and/or the  fulfilment  of any other  requirement)
constitute  an event  described  under  "Events  of  Default"  in the  Terms and
Conditions of the Notes set out in the Offering Circular; and

(12)  Regulation S: neither the Issuer nor its affiliates nor any persons acting
on its or their  behalf  has  engaged  or will  engage in any  directed  selling
efforts (as defined in  Regulation S under the United States  Securities  Act of
1933,  as amended (the  "Securities  Act")) with respect to the Notes and it and
they have complied and will comply with the offering restrictions requirement of
such Regulation.

The  representations  and  warranties of the Issuer in paragraphs (6) and (7) of
this Clause are,  however,  made in reliance on  fulfilment  by the  Managers of
their  representations,  warranties  and  agreements set out in paragraph (B) of
Schedule I attached hereto.

6.    INDEMNITY

(1) The Issuer undertakes to indemnify each Manager and its directors,  officers
and employees, and any affiliates of such Manager (each an "indemnified person")
against any loss, liability,  cost, claim, action or expense (including, but not
limited  to, all  reasonable  costs,  charges and  expenses  paid or incurred in
disputing  or  defending  any of the  foregoing)  which any of them may incur or
which may be made  against  any of them  arising  out of or in relation to or in
connection   with  any   inaccuracy   or  alleged   inaccuracy  in  any  of  the
representations  and  warranties  contained in Clause 5 hereof or in  connection
with any inaccurate  statement or alleged inaccurate  statement contained in the
Offering  Circular  or any  omission  or  alleged  omission  to state  therein a
material  fact  necessary to make the  statements  therein not  misleading.  The
Issuer expressly acknowledges that it shall not be released from such obligation
by reason of the fact that MSSA has assisted in the  preparation of the Offering
Circular.  The Issuer shall not be required to indemnify any indemnified  person
in respect of any inaccuracy or alleged inaccuracy of any of the representations
and warranties herein as to statements in or omissions from the list of Managers
on the cover page of the Offering  Circular or the statements  under the caption
"Subscription and Sale" in the Offering Circular.

(2) Conduct of claims: If any claim,  demand or action is brought or asserted in
respect of which any indemnified person is entitled to be indemnified by another
person (the  "Indemnifier")  under  Clause 3(C) or Clause 6(1) (each a "Claim"),
the following provisions shall apply:

      (a)   Notification:  each  indemnified  person shall  promptly  notify the
            Indemnifier  (but failure to do so shall not relieve the Issuer from
            liability);

      (b)   Assumption  of defence:  the  Indemnifier  shall,  subject to Clause
            6(3),  be  entitled  to assume  the  defence of the  relevant  Claim
            including  the  retention  of  legal   advisers   approved  by  each
            indemnified person, subject to the payment by the Indemnifier of all
            legal and other expenses of such defence;

      (c)   Separate  representation:  if the Indemnifier assumes the defence of
            the relevant  Claim,  each  indemnified  person shall be entitled to
            retain  separate  legal  advisers and to participate in such defence
            but the legal or other expenses incurred in so doing shall,  subject
            to Clause  6(3),  be borne by such  indemnified  person  unless  the
            Indemnifier   has   specifically   authorised   such   retention  or
            participation.


                                      -5-


(3) Conduct by Indemnified Person:  Notwithstanding  Clause 6(2), an indemnified
person may retain  separate  legal  advisers in each relevant  jurisdiction  and
direct the defence of the relevant  Claim and the  Indemnifier  shall  reimburse
such indemnified  person for any legal or other expenses  reasonably so incurred
if:

      (a)   Indemnifier's failure: the Indemnifier (having assumed such defence)
            fails to retain for such  purpose  legal  advisers  approved by such
            indemnified person;

      (b)   Conflict  of  interest:   such  indemnified  person  has  reasonably
            concluded  that  the  use  of  any  legal  advisers  chosen  by  the
            Indemnifier  to represent such  indemnified  person may present such
            legal advisers with a conflict of interest; or

      (c)   Different  defences:  the  actual  or  potential  defendants  in, or
            targets  of,  such  Claim  include  both  the  Indemnifier  and such
            indemnified  person  and  such  indemnified  person  has  reasonably
            concluded that there may be legal defences available to it which are
            different from or additional to those available to the Indemnifier.

(4) Mitigation of loss:  Each  indemnified  person agrees that it shall take all
reasonable steps to mitigate any loss, liability, cost, claim, action or expense
in relation to any claim in respect of which it seeks indemnification hereunder.

(5) Settlement:  The Indemnifier shall not, without the prior written consent of
each  indemnified  party,  settle  or  compromise,  or  consent  to the entry of
judgment  with  respect to, any pending or  threatened  Claim  (irrespective  of
whether any indemnified person is an actual or potential defendant in, or target
of,  such Claim)  unless  such  settlement,  compromise  or consent  includes an
unconditional  release of each indemnified person from all liability arising out
of the matters which are the subject of such Claim. The Indemnifier shall not be
liable to indemnify  any  indemnified  person where the relevant  Claim has been
settled or  compromised  without its prior written  consent  (which shall not be
unreasonably withheld).

(6) Benefit of agreement:  Each of the Managers has entered into this Clause for
itself and as bare trustee for each of its affiliates and each officer, director
and employee of it or any such affiliate  (each, a "Third  Party").  Each of the
Managers shall have an absolute discretion whether or not to exercise or enforce
any right hereunder, be free to deal with its rights hereunder without regard to
the interests of any Third Party,  not be required to account to any Third Party
in respect of any amount  which it receives  hereunder  and not be liable to any
Third Party for any loss arising from any act or omission with respect hereto.

(7) Interpretation:  Term used in this Clause have the meanings given to them by
the Securities Act and the regulations thereunder.

7.  UNDERTAKINGS  BY THE ISSUER  The  Issuer  undertakes  with the  Managers  as
follows:

(A)  Taxes:  The Issuer  will bear and pay all stamp and other  taxes and duties
(including  interest and penalties)  payable  pursuant to the laws applicable in
the United States of America and the United Kingdom on or in connection with the
issue and purchase by the Managers of the Notes and the execution or delivery of
this Agreement and the Contracts.


                                      -6-


(B)  Warranties:  The Issuer will forthwith  notify the Managers if, at any time
prior to payment  of the net  subscription  moneys to the Issuer on the  Closing
Date,  anything  occurs which  renders or may render  untrue or incorrect in any
respect any of the warranties contained in Clause 5.

(C) Amendment to Offering Circular:  The Issuer will notify MSSA if, at any time
prior to completion (in the view of MSSA) of the  distribution of the Notes, any
event  shall have  occurred  as a result of which the  Offering  Circular  would
include an untrue  statement  of a material  fact or omit to state any  material
fact necessary to make the statements therein, in the light of the circumstances
under  which  they are made  when  such  Offering  Circular  is  delivered,  not
misleading  or if for any  other  reason  it  shall  be  necessary  to  amend or
supplement  the Offering  Circular  and,  upon  request  from MSSA,  prepare and
furnish  without  charge to the Managers as many copies as MSSA may from time to
time reasonably  request of an amended Offering  Circular or a supplement to the
Offering Circular which will correct such statement or omission.

(D) Delivery of Offering Circular:  The Issuer will deliver to MSSA three copies
of the Offering  Circular and will deliver to the Managers as many copies of the
Offering Circular as they may reasonably require;

(E) No Announcements:  From the date hereof to, and including,  the Closing Date
the Issuer shall not, without prior notice to MSSA, make any public announcement
which  might   reasonably  be  expected  to  have  an  adverse   effect  on  the
marketability of the Notes.

8.    CONDITIONS PRECEDENT

(A) This  Agreement  and the  obligations  of the Managers to purchase the Notes
under it are conditional upon:

(1) Contracts: the execution and delivery (on or before the Closing Date) of the
Fiscal Agency Agreement and the Deed of Covenant by the respective parties;

(2) Listing: the Stock Exchange having agreed to list the Notes, subject only to
the issue of the  Temporary  Global  Note,  or MSSA  being  satisfied  that such
listing will be granted shortly after the Closing Date;

(3) Legal  Opinions:  on or before  the  Pre-Closing  Date,  there  having  been
delivered  to MSSA on behalf of the  Managers  opinions,  in form and  substance
satisfactory to MSSA, dated the Closing Date of:

      (1)   Dewey Ballantine LLP, New York legal advisers to the Issuer;

      (2)   Mr. B. Wagner, General Counsel of the Issuer; and

      (3)   Clifford Chance, English legal advisers to the Managers;

(4) Auditors'  Letters:  on the date of this  Agreement  and on the  Pre-Closing
Date,  there  having been  delivered  to the  Managers  letters,  in the form or
substantially  in the form set out in Schedule II hereof  dated the date of this
Agreement and the Closing Date, respectively, and addressed to the Managers from
Arthur Andersen, LLP, the auditors of the Issuer;


                                      -7-


(5)  Process  Agent:  on or before  the  Pre-Closing  Date,  there  having  been
delivered to MSSA on behalf of the Managers  evidence that the person  mentioned
in Clause  15(B)(2)  has  agreed to  receive  process  in the  manner  specified
therein;

(6) Compliance:  at the Closing Date (1) the  representations  and warranties of
the Issuer in this  Agreement  being true,  accurate and correct in all material
respects  at, and as if made on,  the  Closing  Date and (2) the  Issuer  having
performed  all of its  obligations  under this  Agreement  to be performed on or
before the Closing  Date and there  having been  delivered to the Managers on or
before the Closing Date a certificate,  dated the Closing Date, signed by a duly
authorised officer of the Issuer to such effect; and

(7) Rating:  at the Closing Date there having occurred no  downgrading,  nor any
notice having been given of (a) any intended or potential downgrading or (b) any
review or possible  change  which does not  indicate  the  direction of any such
change, in the rating accorded to any other debt securities of the Issuer by any
rating agency.

(B) Waiver:  MSSA on behalf of the Managers may, at its discretion and upon such
terms as it thinks fit, waive  compliance with the whole or any part of Clause 8
(other than sub-Clauses (A) (1) and (2)).

9.    CLOSING

(A) Issue of Notes:  At 3.00 p.m.  (London  time) (or such  other time as may be
agreed  between MSSA, on behalf of the Managers,  and the Issuer) on the Closing
Date,  the Issuer will issue and deliver to the  Managers or their order in such
place as MSSA may reasonably require the Temporary Global Note duly executed and
authenticated.

(B) Payment:  Against such delivery the Managers will pay or cause to be paid to
the Issuer the net subscription moneys for the Notes (being the aggregate amount
payable  for the Notes  calculated  at the Issue Price less the  concession  and
commission referred to in Clause 10 and the amount referred to in Clause 11(B)).
MSSA (on  behalf of the  Managers)  shall  cause  such  payment  to be made by a
depositary (the "Common  Depositary") common to Morgan Guaranty Trust Company of
New York,  Brussels office,  as operator of the Euroclear System and Cedel Bank,
societe  anonyme on behalf of the Managers,  in immediately  available  funds to
such  French  Franc  account in Paris as shall be notified by the Issuer to MSSA
evidence  of such  payment  taking  the  form of a  confirmation  by the  Common
Depositary that it has made the relevant payment to the Issuer.

10.   CONCESSIONS AND COMMISSIONS

(A)   Combined management and underwriting commission:  The Issuer shall, on the
      Closing  Date,  pay to  MSSA  (on  behalf  of  the  Managers)  a  combined
      management and underwriting  commission of 0.20 per cent. of the aggregate
      principal amount of the Notes.  Such commission shall be deducted from the
      Issue Price.

(B)   Selling  Concession:  The  Issuer  shall  allow to MSSA (on  behalf of the
      Managers) a selling  concession of 0.20 per cent. of the principal  amount
      of the Notes. Such concession shall be deducted from the Issue Price.


                                      -8-


11.   EXPENSES

(A)  General  Expenses:  The Issuer  agrees to pay the fees and  expenses of the
Fiscal Agent and the Paying Agents in relation to the  preparation and execution
of this Agreement and the Fiscal Agency Agreement,  the issue and authentication
of the  Notes and the  performance  of their  duties  under  the  Fiscal  Agency
Agreement.

(B) Managers'  Expenses:  In addition,  the Issuer will pay an amount in lieu of
reimbursement  of the Managers' legal and other expenses  incurred in connection
with the  issue of the  Notes  and an amount  in  respect  of  certain  expenses
associated  with the issue of the Notes,  all as separately  agreed between MSSA
and the Issuer. Such amount will be deducted from the Issue Price.

(C) Payment: All payments in respect of the costs, fees and expenses referred to
in Clause 11(B) shall be satisfied  by the Issuer  making them to MSSA,  and the
Issuer shall not be concerned with the  apportionment  of such payments  between
the Managers or the payment of them to other persons.

12.   TERMINATION

(A)  Managers'  ability  to  terminate:   Despite  anything  contained  in  this
Agreement,  MSSA on behalf of the Managers may give a termination  notice to the
Issuer at any time  prior to  payment  of the net  subscription  moneys  for the
Notes:

      (a)   if in the opinion of MSSA, circumstances shall be such as:

            (i)   to prevent or to a material  extent  restrict  payment for the
                  Notes in the manner contemplated in this Agreement; or

            (ii)  to  a  material  extent  prevent  or  restrict  settlement  of
                  transactions in the Notes in the market or otherwise; or

      (b)   if in the opinion of MSSA, there shall have been:

            (i)   any change in national or international political,  legal, tax
                  or regulatory conditions; or

            (ii)  any calamity or emergency,

            which  has in its view  caused a  substantial  deterioration  in the
            price and/or value of the Notes.

(B)  Consequences  of  termination:  Upon such notice being given this Agreement
shall  terminate  and be of no further  effect  and no party  shall be under any
liability to any other in respect of this Agreement,  except that (i) the Issuer
shall  remain  liable  under Clause 11 for the payment of the costs and expenses
already  incurred or  incurred  in  consequence  of such  termination,  (ii) the
Managers  shall  remain  liable  under  Clauses  3(B)  and 3(C)  and  (iii)  the
respective obligations of the parties under Clause 13 which would have continued
had the arrangements for the subscription and issue of the Notes been completed,
shall continue.


                                      -9-


13.   SURVIVAL OF REPRESENTATIONS AND OBLIGATIONS

The  representations,  warranties,  agreements,  undertakings and indemnities in
this Agreement shall continue in full force and effect despite completion of the
arrangements for the  subscription  and issue of the Notes or any  investigation
made by or on behalf of the Managers or any of them.

14.   COMMUNICATIONS

Any  communication   shall  be  given  by  letter,  or  by  telex  or  facsimile
transmission in the case of notices to the Issuer, to it at:

Omnicom Group Inc.
437 Madison Avenue
New York, N.Y. 10022

U.S.A.

Fax no.: (212) 415 3530
Attention: Treasurer

and in the case of notices from the Issuer to the Managers, to MSSA at:

25 rue de Balzac
75406 Paris
Cedex 08

Telephone No.: 00 331 5377 7000
Telex No.: 644303
Fax No.: 00 331 5377 7099
Attention: Head of Syndicate

Any such  communication  shall take effect, in the case of a letter, at the time
of delivery,  in the case of telex at the time of receipt of answerback,  and at
the  time of  telephonic  confirmation  of  receipt,  in the case of  notice  by
facsimile.

Any communication not by letter shall be confirmed by letter but failure to send
or  receive  the  letter of  confirmation  shall  not  invalidate  the  original
communication.

15.   GOVERNING LAW AND JURISDICTION

(A)  Governing  Law:  This  Agreement  shall be  governed  by and  construed  in
accordance with English law.

(B) Jurisdiction:

(1) The courts of England are to have  jurisdiction to settle any disputes which
may arise out of or in connection  with this Agreement and accordingly any legal
action or  proceedings  arising  out of or in  connection  with  this  Agreement
("Proceedings") may be brought in such courts. The Issuer irrevocably submits to
the  jurisdiction  of such courts for the purposes of any Proceedings and waives
any objection to any  Proceedings in such courts whether on the grounds of venue
or on the ground  that the  Proceedings  have been  brought  in an  inconvenient
forum.  This submission is for the benefit of each of the Managers and shall not
limit the right of any of them to take Proceedings in any other


                                      -10-


court of competent  jurisdiction  nor shall the taking of  Proceedings in one or
more jurisdictions  preclude the taking of Proceedings in any other jurisdiction
(whether concurrently or not).

(2)  The  Issuer  irrevocably  appoints  Omnicom  Finance  Limited  of  239  Old
Marylebone  Road,  London NW1 5QT as its authorised agent for service of process
in  England.  If for any  reason  such  agent  shall  cease to be such agent for
service of process,  the Issuer shall forthwith,  on request of MSSA,  appoint a
new agent for  service of process in England  acceptable  to MSSA and deliver to
MSSA a copy of the new agent's acceptance of that appointment within 30 days.

Nothing in this  Agreement  shall affect the right to serve process in any other
manner permitted by law.

This Agreement has been entered into on the date stated at the beginning.

This  Agreement  may be  executed in any number of  counterparts,  each of which
shall be deemed an original.  Any party may enter into this Agreement by signing
any such counterpart.

OMNICOM GROUP INC.

By:  DENIS STREIFF

MORGAN STANLEY S.A.

By:  ALICE BONARDI

SOCIETE GENERALE

By:  ALICE BONARDI

DRESDNER BANK AKTIENGESELLSCHAFT
BANQUE NATIONALE DE PARIS
PARIBAS
CREDIT AGRICOLE INDOSUEZ
CREDIT COMMERCIAL DE FRANCE
NATEXIS BANQUE
By:  ALICE BONARDI


                                      -11-


                                   SCHEDULE I

(A)  General : No action  has been or will be taken in any  jurisdiction  by the
Managers or the Issuer  that would  permit a public  offering  of the Notes,  or
possession or  distribution  of the Offering  Circular (in  preliminary or final
form) or any other offering or publicity  material relating to the Notes, in any
country or jurisdiction where action for that purpose is required.  Each Manager
will comply with all applicable  laws and  regulations in each  jurisdiction  in
which it acquires,  offers,  sells or delivers Notes or has in its possession or
distributes  the Offering  Circular (in  preliminary  or final form) or any such
other  material,  in all cases at its own expense.  No Manager is  authorised to
make any  representation or to use any information in connection with the issue,
subscription  and sale of the Notes  other  than as  contained  in the  Offering
Circular or any amendment or supplement thereto.

(B) United States:  The Notes have not been and will not be registered under the
Securities Act and may not be offered or sold within the United States or to, or
for the account or benefit of, U.S. persons except in accordance with Regulation
S under the Securities Act or pursuant to an otherwise  available exemption from
the  registration  requirements of the Securities  Act. Each Manager  represents
that it has offered  and sold the Notes,  and agrees that it will offer and sell
the Notes (i) as part of their distribution at any time and (ii) otherwise until
40 days after the later of the  commencement  of the  offering  and the  Closing
Date, only in accordance with Rule 903 of Regulation S under the Securities Act.
Accordingly,  neither it, its  affiliates  nor any person acting on its or their
behalf have engaged or will engage in any directed  selling efforts with respect
to the Notes,  and it and they have  complied  and will comply with the offering
restrictions  requirement of Regulation S. Each Manager agrees that, at or prior
to  confirmation  of sale of the Notes,  it will have sent to each  distributor,
dealer or person receiving a selling concession,  fee or other remuneration that
purchases Notes from it during the restricted period a confirmation or notice to
substantially the following effect:

      "The  Securities  covered hereby have not been  registered  under the U.S.
      Securities Act of 1933 (the  "Securities  Act") and may not be offered and
      sold  within the United  States or to, or for the  account or benefit  of,
      U.S.  persons  (i) as  part  of  their  distribution  at any  time or (ii)
      otherwise  until  40 days  after  the  later  of the  commencement  of the
      offering and the closing date,  except in either case in  accordance  with
      Regulation S under the  Securities  Act. Terms used above have the meaning
      given to them by Regulation S."

Terms used in this paragraph have the meanings given to them by Regulation S.

Except as contemplated by this Agreement, the Managers have not entered and will
not enter, into any contractual  arrangement with respect to the distribution or
delivery of the Notes,  except with their  affiliates  or with the prior written
consent of the Issuer.

In addition, each of the Managers:

(1) except to the extent permitted under U.S. Treas. Reg. ss.1.163-5(c)(2)(i)(D)
(the "D Rules"),  (a) represents that it has not offered or sold, and during the
restricted period agrees that it will not offer or sell, Notes in bearer form to
a person  who is within  the  United  States or its  possessions  or to a United
States  person,  and (b) it has not  delivered  and will not deliver  within the
United States or its possessions  definitive  Notes in bearer form that are sold
during the restricted period;


                                      -12-


(2) represents and agrees that it has, and throughout the restricted period will
have, in effect procedures  reasonably  designed to ensure that its employees or
agents who are directly  engaged in selling  Notes in bearer form are aware that
such Notes may not be offered or sold during the  restricted  period to a person
who is within the United States or its possessions or to a United States person,
except as permitted by the D Rules;

(3)  if it is a  United  States  person,  each  Manager  represents  that  it is
acquiring  the Notes for purposes of resale in  connection  with their  original
issue and if it retains  Notes in bearer form for its own account,  will only do
so  in  accordance  with  the  requirements  of  U.S.  Treas.   Reg.   ss.1.163-
5(c)(2)(i)(D)(6); and

(4) with  respect to each  affiliate  that  acquires  from any Manager  Notes in
bearer  form for the  purpose  of  offering  or selling  such  Notes  during the
restricted   period,   each   Manager   either  (a)  repeats  and  confirms  the
representations  and agreements  contained in clauses (1), (2) and (3) on behalf
of such  affiliate or (b) agrees that it will obtain from such affiliate for the
benefit of the Issuer the  representations  and agreements  contained in clauses
(1), (2) and (3).

Terms  used in this  paragraph  have  the  meanings  given  to them by the  U.S.
Internal Revenue Code and regulations thereunder, including the D Rules.

(C) United  Kingdom:  Each Manager  represents to and agrees with the Issuer and
each other Manager that:

      (a) No offer to public:  it has not  offered or sold and will not offer or
      sell any Notes to persons in the United Kingdom prior to the expiry of the
      period  of six  months  from the  Closing  Date  except to  persons  whose
      ordinary  activities  involve  them in  acquiring,  holding,  managing  or
      disposing of investments (as principal or agent) for the purposes of their
      businesses or otherwise in circumstances  which have not resulted and will
      not  result in an offer to the  public in the  United  Kingdom  within the
      meaning of the Public Offers of Securities Regulations 1995;

      (b)  General  compliance:  it  has  complied  and  will  comply  with  all
      applicable  provisions of the Financial  Services Act 1986 with respect to
      anything  done by it in  relation  to the  Notes  in,  from  or  otherwise
      involving the United Kingdom; and

      (c)  Investment  advertisements:  it has only issued or passed on and will
      only issue or pass on in the United Kingdom any document received by it in
      connection  with  the  issue of the  Notes  to a  person  who is of a kind
      described in article 11(3) of the Financial  Services Act 1986 (Investment
      Advertisements)  (Exemptions)  Order  1996 or is a  person  to  whom  such
      document may otherwise lawfully be issued or passed on.

(D) Republic of France:  Each Manager  represents  and agrees that the Notes are
being issued  outside the Republic of France and that, in connection  with their
initial  distribution,  it has not  offered  or sold and will not offer or sell,
directly or indirectly,  any Notes to the public in the Republic of France,  and
that it has not  distributed  and will not distribute or cause to be distributed
to the public in the  Republic  of France  the  Offering  Circular  or any other
offering material relating to the Notes.


                                      -13-


                                   SCHEDULE II

                                     Part I

                                     Arthur
                                    Anderson

June 22, 1998

Morgan Stanley S.A.
c/o Pierre Massera
25 Rue de Balzac
75008 Paris France
for itself and on behalf of the
Managers of the Note issue which
are party to the Subscription Agreement
dated 22 June 1998

Dear Sirs:

We have audited the consolidated balance sheets of Omnicom Group Inc. and
subsidiaries (the "Company" as of December 31,1007 and 1996, and the
consolidated statements of income, shareholders' equity, and changes in
financial position (cash flows) for each of the three years in the period ended
December 31, 1997, and the related financial statement schedule, all
incorporated by reference in the Company's Offering Circular (the "Offering
Circular") covering the issuance of FRF 1,000,000,000, 5.20% Notes due 2005 (the
"Notes"); or report with respect thereto dated February 18, 1998 (except for
Note 14 as to which the date is March 24, 1998), included in the Company's
Annual Report on Form 10-K for the year ended December 31, 1997, is also
incorporated by reference in the Offering Circular.

In connection with the Offering Circular:

      1.    We are independent certified public accountants with respect to the
            Company within the meaning of Rule 101 of the American Institute of
            Certified Public Accountants' Code of Professional Conduct, and in
            interpretations and rulings.

      2.    In our opinion, the financial statements audited by us, and
            incorporated by reference in the Offering Circular, comply in form
            in all material respects with the applicable accounting requirements
            of the Securities Exchange Act of 1934 (the "Act") and the related
            published rules and regulations thereunder.

      3.    We have not audited any financial statements of the Company as of
            any date or for any period subsequent to December 31, 1997; although
            we have conducted an audit for the year ended December 31, 1997, the
            purpose (and therefore the scope) of the audit was to enable us to
            express our opinion of the consolidated financial statements as of
            December 31, 1997, and for the year then ended, but not of the
            consolidated financial statements for any interim period within the
            year. Therefore, we are unable to and do not express any opinion on
            the unaudited balance sheet as of March 31, 1998 or the statements
            of income, retained earnings and changes in financial position (cash
            flows) for the three month period ended March 31, 1998 and 1997,
            incorporated by reference in the Offering Circular, or on the
            financial position, resulting of operations or changes in financial
            position (cash flows) as of any date or for any period subsequent to
            December 31, 1997.


                                       -14-



                                     Arthur
                                    Andersen

Morgan Stanley S.A.
Page 2
June 22, 1998

      4.    For purposes of this letter, we have read the 1998 minutes of the
            meetings of the Board of Directors, Audit Committee and Compensation
            Committee of Omnicom Group Inc. as set forth in the minute books as
            of June 22, 1998, officials of the Company having advised us that
            the minutes of all such meetings through the date were set forth
            therein; we have carried out other procedures to June 22, 1998, as
            follows:

            a.    With respect to the three-month periods ended March 31, 1998,
                  1997 and 1996, we have:

                  i.    Read the unaudited condensed consolidated balance sheets
                        as of March 31, 1998 and 1997 and unaudited condensed
                        consolidated statements of income for the three-month
                        periods ended March 31, 1998, 1997 and 1996,
                        incorporated by reference in the Offering Circular, and
                        agree the amounts contained therein to the Company's
                        accounting records as of March 31, 1998 and 1997 and for
                        the three-month periods ended March 31, 1998, 1997 and
                        1996.

                  ii.   Inquired of certain officials of the Company who have
                        responsibility for financial and accounting matters
                        whether the unaudited condensed consolidated financial
                        statements referred to in a(i) and above: (1) are in
                        conformity with generally accepted accounting principles
                        in the United states applied on a basis substantially
                        consistent with that of the audited consolidated
                        financial statements incorporated by reference in the
                        Offering Circular, and (2) comply as to form in all
                        material respects with the applicable accounting
                        requirements of the Act and the related published rules
                        and regulations. Those officials stated that the
                        unaudited condensed consolidated financial statements
                        (1) are in conformity with generally accepted accounting
                        principles in the United States applied on a basis
                        substantially consistent with that of the audited
                        consolidated financial statements incorporated by
                        reference in the Offering Circular, and (2) comply as to
                        form in all material respects with the applicable
                        accounting requirements of the Act and the related
                        published rules and regulations.

            b.    With respect to the period from April 1, 1998 through April
                  30, 1998, we have:

                  i.    Read the unaudited condensed consolidated statements of
                        income of the Company for the four-month periods ended
                        April 30, 1998 and 1997 furnished us by the Company.
                        [ILLEGIBLE] of the Company having advised us that no
                        such financial statements as of any [ILLEGIBLE] any
                        period subsequent to April 30, 1998 were available.

                  ii.   Inquired of certain officials of the Company who have
                        responsibility for financial and accounting matter
                        whether the unaudited condensed consolidated statements
                        of income referred to in (b)(i) are stated on a basis
                        substantially consistent with that of the audited
                        consolidated statements of income incorporated by
                        reference in the Offering Circular. Those officials
                        stated that the unaudited condensed consolidated
                        statements of income referred to in b(i) are stated on a
                        basis substantially consistent with that of the audited
                        consolidated statements of income incorporated by
                        reference in the Offering Circular.


                                       -15-



                                     Arthur
                                    Andersen

Morgan Stanley S.A.
Page 3
June 22, 1998

      5.    Because, as previously mentioned, no consolidated balance sheet,
            statement of shareholders' equity statement of changes in financial
            position (cash flows) as of any date or for any period subsequent to
            March 31, 1998, or statement of income for any period subsequent to
            April 30, 1998 are available, the procedures carried out by us with
            respect to changes in the consolidated balance sheet, statement of
            shareholders' equity, or statement of changes in financial position
            (cash flows) items after March 31, 1998, or for changes in the
            consolidated statement of income for any period subsequent to April
            30, 1998 have been more limited than those with respect to the
            periods referred to in 4. We have inquired of certain officials of
            the Company who have responsibility for financial and accounting
            matters as to whether (a) at June 22, 1998, there was any change in
            capital stock, increase in long-term debt, increase in consolidated
            net current liabilities or decrease in shareholders' equity of the
            Company as compared with amounts shown on the March 31, 1998
            unaudited condensed consolidated balance sheet incorporated by
            reference in the Offering Circular or (b) for the period from May 1,
            1998 to June 22, 1998, there were any decreases, as compared with
            the corresponding period in the preceding year, in consolidated
            commissions and fees or in the total or per-share amounts of income
            before extraordinary items or of net income. Those officials stated
            that, except for the matters set out below in 5.a.,(1) at June 22,
            1998, there was no change in capital stock, no increase in long-term
            debt, no increase in consolidated net current liabilities, and no
            decrease in shareholders' equity of the Company as compared with
            amounts shown on the March 31, 1998 unaudited condensed consolidated
            balance sheet incorporated by reference in the Offering Circular and
            (2) for the period from May 1, 1998 to June 22, 1998, there were no
            decreases, as compared with the corresponding period in the
            preceding year, in consolidated commissions and fees or in the total
            or per-share amounts of income before extraordinary items or of net
            income.

            a.    The officials referred to in 5 above stated that the Company's
                  consolidated net current liabilities have increased between
                  March 31 and June 30 of each of the preceding two years (1997
                  and 1996). Although there is no consolidated balance sheet
                  available for any date subsequent to March 31, 1998, those
                  officials further stated it is possible that had a
                  consolidated balance sheet as of June 22, 1998 have been
                  available, it would disclose an increase in consolidated net
                  current liabilities compared with amounts shown on the March
                  31, 1998 unaudited condensed consolidated balance sheet
                  incorporated by reference in the Offering Circular, as a
                  result of normal seasonal factors offset by the long-term
                  refinancing of certain short-term indebtedness. In addition,
                  although no consolidated balance sheet is available subsequent
                  to March 31, 1998, those officials stated it is probable that
                  were a consolidated balance sheet to have been available, it
                  would disclose an increase in long-term debt as a result of
                  the refinancing of short-term indebtedness, repurchases of the
                  Company's common stock, acquisition related payments and other
                  factors. Additionally, Company officials have informed us that
                  the number of shares of common stock issued and outstanding
                  was 169,712,975 at June 19, 1998, as compared to 169,970,855
                  at March 31, 1998.

      6.    For accounting data shown on pages 19 to 22 of the Offering Circular
            pertaining to the years ended December 31, 1997, 1996 and 1995, and
            for the quarters ended March 31, 1998, 1997 and 1996, we have
            compared this data with the financial information contained in the
            audited annual Form 10-K and unaudited quarterly Form 10-Q's and
            found them to be in agreement.


                                       -16-


                                     Arthur
                                    Andersen

Morgan Stanley S.A.
Page 3
June 22, 1998

      7.    For purposes of this letter, we have performed additional procedures
            described in Schedule A under the heading "Procedures and Findings",
            which were applied as indicated with respect to the items so
            identified.

            It should be understood that we have no responsibility for
            establishing (and did not establish) the scope and nature of the
            procedures enumerated in paragraphs 3 through 7 above; rather the
            procedures enumerated therein are those the requesting party asked
            us to perform. Accordingly, we make no representations regarding
            questions of legal interpretation, nor do we provide any assurance
            as to matters relating to the Company's solvency, adequacy of its
            capital or ability to pay its debts, or regarding the sufficiency
            for your purposes of the procedures enumerated in the preceding
            paragraphs; also, such procedures would not necessarily reveal any
            material misstatement of amounts discussed above. Further, we have
            addressed ourselves solely to the foregoing data as set forth in the
            Offering Circular and make no representations regarding the adequacy
            of disclosure or regarding whether any material facts have been
            omitted. This letter relates only to the financial statement items
            specified above and does not extend to any financial statements of
            the Company.

            The foregoing procedures do not constitute an audit conducted in
            accordance with generally accepted auditing standards in the United
            States. We make no representations regarding the sufficiency of the
            foregoing procedures for your purposes. Had we performed additional
            procedures or had we conducted an audit or a review, other matters
            might have come to our attention that would have been reported to
            you.

            The procedures herein should not be taken to supplant any additional
            inquiries of procedures that you would undertake in your
            consideration of the proposed offering.

            This letter is solely for the information of the addressee and to
            assist Morgan Stanley S.A. and the other Managers (the "Managing
            Group") in conducting and documenting their investigation of the
            affairs of the Company in connection with the offering of the Notes
            covered by the Offering Circular, and it is not to be used,
            circulated, quoted, or otherwise referred to within or without the
            Managing Group for any purpose, including but not limited to the
            registration, purchase, or sale of Notes, nor is it to be filed with
            or referred to in whole or in part in the Offering Circular or any
            other document, except that reference may be made to it in any list
            of closing documents pertaining to the offering of the Notes covered
            by the Offering Circular.

            Very truly yours,

            /s/ Arthur Anderson LLP
            -----------------------
            ARTHUR ANDERSEN LLP


                                      -17-


                                   Schedule A

                   PROCEDURES AND FINDINGS FOR WORK PERFORMED
                       WITH RESPECT TO INFORMATION IN THE
                       OFFERING CIRCULAR OR IN DOCUMENTS
               INCORPORATED BY REFERENCE IN THE OFFERING CIRCULAR

Reference           Description                    Procedures and Findings
- ---------           -----------                    -----------------------

Description of the  The statement that in 1997    We traced and recomputed
Issuer, page 13     and 1996, 50% and 51%         the indicated percentages
                    respectively, of Omnicom      to a schedule prepared by
                    Group's billing came from     the Company, noting
                    its non-U.S. operations.      agreement. We noted the
                                                  billings percentages do not
                                                  represent percentage of 
                                                  domestic and international 
                                                  invoices rendered to clients, 
                                                  but rather the term "billings"
                                                  as used in this content is 
                                                  used to describe the volume of
                                                  advertising purchased by 
                                                  clients which is derived based
                                                  upon methods disclosed 
                                                  under (*) in the Company's 
                                                  1997 Annual Report to 
                                                  Shareholders in the 
                                                  Comparative Highlights table.

Clients, page 15    The statement that            We traced and recomputed the
                    Omnicom's ten largest         indicated percentages to a
                    clients accounted for         schedule prepared by the
                    approximately 20% of          Company, noting agreement.
                    1997 commissions and fees.

The Issuer's        The actual components         We traced or recomputed
Capitalisation,     of short-term and             the indicated amounts to
page 18             long-term debt as             data as shown on a schedule
                    of March 31, 1998 and         prepared by the Company,
                    March 31, 1997.               noting agreement.

The Issuer's        The actual components         We traced the indicated
Capitalisation,     of shareholders' equity       amounts to data as shown
pages 18            as of March 31, 1998          on a schedule prepared by
                    and March 31, 1997.           the Company, noting
                                                  agreement.


                                      -18-


Reference           Description                   Procedures and Findings
- ---------           -----------                   -----------------------

The Issuer's        Total capitalisation          We added total long-term
Capitalisation,     at March 31, 1998             debt and total shareholders'
page 18             and March 31, 1997.           equity, noting agreement
                                                  with total capitalisation at
                                                  March 31, 1998 and
                                                  March 3, 1997.


                                      -19-



                                     Part II

Morgan Stanley S.A.
on behalf of the managers of the
issue mentioned below

                                                                    24 June 1998

Dear Sirs,

                               OMNICOM GROUP INC.
                         FRF1,000,000,000 5.20 per cent.
                                 Notes due 2005

We refer to our  letter of 22 June  1998.  We are  pleased to advise you that we
reaffirm the contents of that letter as at today's date.

This  letter is given  solely for the  information  of the persons to whom it is
addressed and may not be relied upon by any other person.

Yours faithfully,

Arthur Andersen LLP

By:

                                                                                
                                     - 20 -