CONFORMED COPY

                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934

For Quarter Ended:  September 30, 1997

Commission file number:  1-10551

                               Omnicom Group Inc.
             (Exact name of registrant as specified in its charter)

     New York                                                    13-1514814    
(State or other jurisdiction of                                (IRS Employer
 incorporation or organization)                              Identification No.)

437 Madison Avenue,                                                  10022
New York, New York                                                (Zip Code)
(Address of principal executive offices)                          

                                 (212) 415-3600
              (Registrant's telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days. Yes |X|  No
                                        
The number of shares of common stock of the Company  issued and  outstanding  at
October 31, 1997 is 81,011,000.



                       OMNICOM GROUP INC. AND SUBSIDIARIES
                                      INDEX

                                                                        Page No.
                                                                        --------

PART I.       FINANCIAL INFORMATION

  Item 1.     Financial Statements:

              Consolidated Condensed Balance Sheets -
                 September 30, 1997, December 31, 1996 and
                 September 30, 1996                                         2

              Consolidated Condensed Statements of Income -
                 Three Months Ended September 30, 1997 and 1996
                 Nine Months Ended September 30, 1997 and 1996              3

              Consolidated Condensed Statements of Cash Flows -
                 Nine Months Ended September 30, 1997 and 1996              4

              Notes to Consolidated Condensed Financial
                 Statements                                                5-8

  Item 2.     Management's Discussion of Financial Condition
                 and Results of Operations                                 9-14


PART II.      OTHER INFORMATION


  Item 6.     Exhibits                                                      15


                                     - 1 -


                         PART I. FINANCIAL INFORMATION
                          Item 1. Financial Statements
                       OMNICOM GROUP INC. AND SUBSIDIARIES
                      CONSOLIDATED CONDENSED BALANCE SHEETS
                             (Dollars in Thousands)


              Assets                                                   September 30,   December 31,  September 30,
             --------                                                       1997           1996           1996
                                                                        -----------    -----------    -----------
                                                                                                     
Current assets: 
   Cash and cash equivalents                                            $   238,253    $   510,267    $   191,027
   Investments available-for-sale, at market, which approximates cost        71,644         12,841         15,742
   Accounts receivable, less allowance for doubtful accounts
     of $27,139, $25,642 and $21,453                                      1,691,987      1,555,411      1,448,804
   Billable production orders in process                                    217,275        156,667        186,565
   Prepaid expenses and other current assets                                253,434        189,799        221,592
                                                                        -----------    -----------    -----------
         Total current assets                                             2,472,593      2,424,985      2,063,730

Furniture, equipment and leasehold improvements, less
  accumulated depreciation and amortization of $329,403,
  $301,102 and $300,069                                                     228,789        221,655        212,623
Investments in affiliates                                                   277,662        223,918        196,142
Intangibles, less amortization of $215,369, $198,880 and $187,632         1,161,287      1,000,312        913,243
Deferred tax benefits                                                        75,693         79,828         65,550
Deferred charges and other assets                                           172,055        105,245        106,759
                                                                        -----------    -----------    -----------
         Total assets                                                   $ 4,388,079    $ 4,055,943    $ 3,558,047
                                                                        ===========    ===========    ===========
       Liabilities and Shareholders' Equity
       ------------------------------------
Current liabilities:
   Accounts payable                                                     $ 1,838,341    $ 2,070,026    $ 1,488,205
   Payable to banks                                                         104,881          8,772         61,143
   Other accrued liabilities                                                750,439        717,869        636,469
   Accrued taxes on income                                                   78,331         66,409         42,950
                                                                        -----------    -----------    -----------
         Total current liabilities                                        2,771,992      2,863,076      2,228,767

Long term debt                                                              596,503        204,744        428,139
Deferred compensation and other liabilities                                 140,205        124,739        109,152
Minority interests                                                           59,583         62,706         57,385

Shareholders' equity:
   Common stock                                                              43,416         43,144         43,144
   Additional paid-in capital                                               570,159        554,511        554,420
   Retained earnings                                                        500,435        419,072        374,646
   Unamortized restricted stock                                             (51,368)       (39,445)       (43,551)
   Cumulative translation adjustment                                        (46,145)         3,490        (26,519)
   Treasury stock                                                          (196,701)      (180,094)      (167,536)
                                                                        -----------    -----------    -----------
         Total shareholders' equity                                         819,796        800,678        734,604
                                                                        -----------    -----------    -----------
         Total liabilities and shareholders' equity                     $ 4,388,079    $ 4,055,943    $ 3,558,047
                                                                        ===========    ===========    ===========


The accompanying  notes to consolidated  condensed  financial  statements are an
integral part of these balance sheets.


                                       -2-


                       OMNICOM GROUP INC. AND SUBSIDIARIES
                   CONSOLIDATED CONDENSED STATEMENTS OF INCOME
                  (Dollars in Thousands, Except Per Share Data)


                                               Three Months Ended                Nine Months Ended 
                                                  September 30,                     September 30,
                                               -------------------               -------------------
                                               1997           1996               1997           1996
                                               ----           ----               ----           ----
                                                                                       
Revenues:                                                               
   Commissions and fees                      $746,839       $631,772         $2,229,757     $1,889,838
                                                                        
Operating expenses:                                                     
   Salaries and related costs                 452,927        385,995          1,318,612      1,115,803
   Office and general expenses                214,028        186,173            634,397        552,118
                                             --------       --------         ----------     ----------
           Total operating expenses           666,955        572,168          1,953,009      1,667,921
                                             --------       --------         ----------     ----------
                                                                        
Operating profit                               79,884         59,604            276,748        221,917
                                                                        
Net interest expense:                                                   
   Interest and dividend income                (5,532)        (3,043)           (14,789)       (10,104)
   Interest paid or accrued                    12,356          7,487             30,923         26,745
                                             --------       --------         ----------     ----------
           Net interest expense                 6,824          4,444             16,134         16,641
                                             --------       --------         ----------     ----------
                                                                        
Income before income taxes                     73,060         55,160            260,614        205,276
                                                                        
Income taxes:                                                           
   Federal                                     10,557          9,255             39,497         35,192
   State and local                              4,935          3,722             15,397         10,707
   International                               14,387          9,259             51,296         37,034
                                             --------       --------         ----------     ----------
           Total income taxes                  29,879         22,236            106,190         82,933
                                             --------       --------         ----------     ----------
                                                                        
Income after income taxes                      43,181         32,924            154,424        122,343
Equity in affiliates                            4,601          3,509             16,027         10,585
Minority interests                             (6,291)        (4,200)           (22,493)       (16,829)
                                             --------       --------         ----------     ----------
           Net income                        $ 41,491       $ 32,233         $  147,958     $  116,099
                                             ========       ========         ==========     ==========
                                                                        
Earnings per share:                                                     
- -------------------
   Net income:                                                          
           Primary                           $   0.51       $   0.42          $    1.82      $    1.53
           Fully diluted                     $   0.51       $   0.42          $    1.82      $    1.50
                                                                        
Dividends declared per common share          $   0.25       $   0.20          $    0.65      $    0.55

                                                                        
The accompanying  notes to consolidated  condensed  financial  statements are an
integral part of these statements.


                                       -3-


                       OMNICOM GROUP INC. AND SUBSIDIARIES
                 CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS
                             (Dollars in Thousands)



                                                                    Nine Months Ended
                                                                      September 30,
                                                                 ----------------------
                                                                    1997         1996
                                                                 ---------    ---------
                                                                              
Cash flows from operating activities:
  Net income                                                     $ 147,958    $ 116,099
  Adjustments to reconcile net income to net cash                
     used for operating activities:                              
   Depreciation and amortization of tangible assets                 42,895       36,736
   Amortization of intangible assets                                29,421       22,837
   Minority interests                                               22,493       16,829
   Earnings of affiliates in excess of dividends received           (9,641)        (418)
   Decrease in deferred tax benefits                                 2,165        5,172
   Provision for losses on accounts receivable                       5,030        2,287
   Amortization of restricted shares                                12,924       10,100
   (Increase) decrease in accounts receivable                     (143,256)      94,964
   Increase in billable production                                 (62,714)     (52,736)
   Increase in other current assets                                (43,209)     (58,975)
   Decrease in accounts payable                                   (210,770)    (290,891)
   Decrease in other accrued liabilities                            (4,019)     (90,360)
   Increase (decrease) in accrued income taxes                       9,606       (1,438)
   Other                                                           (37,563)        (110)
                                                                 ---------    ---------
     Net cash used for operating activities                       (238,680)    (189,904)
                                                                 ---------    ---------
                                                                 
Cash flows from investing activities:                            
   Capital expenditures                                            (47,251)     (37,855)
   Payments for purchases of equity interests in                 
    subsidiaries and affiliates, net of cash acquired             (300,622)    (117,761)
   Proceeds from sales of equity interests in                    
    subsidiaries and affiliates                                        466       49,934
   Payments for purchases of investments available-for-sale       
    and other investments                                          (88,526)     (13,318)
   Proceeds from sales of investments available-for-sale         
    and other investments                                           34,056       20,345
                                                                 ---------    ---------
     Net cash used for investing activities                       (401,877)     (98,655)
                                                                 ---------    ---------
                                                                 
Cash flows from financing activities:                            
   Net borrowings under lines of credit                             76,784       38,539
   Share transactions under employee stock plans                    26,247       12,482
   Proceeds from issuance of principal of debt obligations         468,447      252,502
   Repurchase of debt obligations                                  (38,172)        --
   Dividends and loans to minority stockholders                    (27,934)     (18,297)
   Dividends paid                                                  (47,704)     (38,532)
   Purchase of treasury shares                                     (52,223)     (85,812)
                                                                 ---------    ---------
     Net cash provided by financing activities                     405,445      160,882
                                                                 ---------    ---------
                                                                 
Effect of exchange rate changes on cash and cash equivalents       (36,902)       4,705
                                                                 ---------    ---------
   Net decrease in cash and cash equivalents                      (272,014)    (122,972)
Cash and cash equivalents at beginning of period                   510,267      313,999
                                                                 ---------    ---------
Cash and cash equivalents at end of period                       $ 238,253    $ 191,027
                                                                 =========    =========
                                                                 
Supplemental Disclosures:                                        
   Income taxes paid                                             $  96,750    $  89,412
                                                                 =========    =========
   Interest paid                                                 $  27,049    $  28,834
                                                                 =========    =========

                                                                 
The accompanying  notes to consolidated  condensed  financial  statements are an
integral part of these statements.


                                      - 4 -



                       OMNICOM GROUP INC. AND SUBSIDIARIES
              NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS

1)       The consolidated condensed interim financial statements included herein
         have been prepared by the Company, without audit, pursuant to the rules
         and  regulations  of the Securities  and Exchange  Commission.  Certain
         information  and footnote  disclosures  normally  included in financial
         statements  prepared in accordance with generally  accepted  accounting
         principles  have been  condensed or omitted  pursuant to such rules and
         regulations.

2)       These  statements   reflect  all  adjustments,   consisting  of  normal
         recurring  accruals which, in the opinion of management,  are necessary
         for a fair presentation of the information  contained therein.  Certain
         reclassifications  have been made to the  September  30, 1996  reported
         amounts to conform  them with the  September  30, 1997 and December 31,
         1996 presentation.  These consolidated  condensed financial  statements
         should  be  read  in  conjunction  with  the   consolidated   financial
         statements and notes thereto included in the Company's annual report on
         Form 10-K for the year ended December 31, 1996.

3)       Results  of  operations  for  interim   periods  are  not   necessarily
         indicative of annual results.               
  

                                      - 5 -



                       OMNICOM GROUP INC. AND SUBSIDIARIES
        NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS (CONTINUED)


4)   Primary  earnings  per share is based upon the weighted  average  number of
     common shares and common share equivalents  outstanding during each period.
     Fully  diluted  earnings per share is based on the above,  and if dilutive,
     adjusted  for the assumed  conversion  of  convertible  debentures  and the
     assumed  increase  in net  income for the after tax  interest  cost of such
     debentures.  At September  30,  1997,  the 4.25%  Convertible  Subordinated
     Debentures  had been  outstanding  since  January  3,  1997.  In 1996,  the
     4.5%/6.25% Step-Up Convertible Subordinated Debentures had been outstanding
     until the September 5, 1996  redemption  date. The number of shares used in
     the  computations  of primary and fully diluted  earnings per share were as
     follows:

                            Three Months                      Nine Months
                         Ended September 30,              Ended September 30,
                         -------------------              ------------------- 
                         1996           1997              1996           1997
                         ----           ----              ----           ----
Primary               81,434,700     76,629,100        81,286,300     76,120,500
Fully diluted         81,564,300     80,702,800        81,527,500     80,997,000

         For  purposes of  computing  fully  diluted  earnings  per share on net
     income for the three months and nine months ended  September 30, 1997,  the
     Company's 4.25% Convertible  Subordinated  Debentures were not reflected in
     the computation as their inclusion would have been anti-dilutive.

         In February 1997, the  FASB issued SFAS No. 128,  "Earnings per Share".
     Under SFAS No. 128, the presentation of Primary


                                      - 6 -


     and Fully Diluted  Earnings Per Share will be replaced by Basic and Diluted
     Earnings Per Share. Adoption of SFAS No. 128 is required for periods ending
     after December 15, 1997, at which time  restatement  for prior periods will
     be  necessary.  Had the  provisions  of SFAS No.  128 been in  effect as of
     September 30, 1997, the Company would have reported the following  earnings
     per share information:

                               Three Months                 Nine Months
                            Ended September 30,         Ended September 30,
                            -------------------         -------------------
                             1997        1996            1997        1996
                             ----        ----            ----        ----
       Earnings per share:
       -------------------
       Basic                $ 0.52      $ 0.43          $ 1.85      $ 1.55
       Diluted              $ 0.51      $ 0.42          $ 1.82      $ 1.50
            
5)   On February 28, 1997, the Company  exchanged 544,487 shares of common stock
     for all of the  outstanding  shares of Cline Davis & Mann,  Inc.  and Gavin
     Anderson & Company (Japan), Inc. These combinations have been accounted for
     as poolings of interests. The assets, liabilities, shareholders' equity and
     results  of  operations  of  the   companies   acquired  are  not,   either
     individually or in the aggregate,  material to the Company and,  therefore,
     the Company's prior year financial statements have not been restated.
    
6)   On January 3, 1997, the Company issued  $218,500,000  of 4.25%  Convertible
     Subordinated  Debentures with a scheduled  maturity in 2007. The debentures
     are


                                      -7-


                       OMNICOM GROUP INC. AND SUBSIDIARIES
        NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS (CONTINUED)

          convertible  into common stock of the Company at a conversion price of
          $63.00 per share subject to adjustment  in certain  events.  Debenture
          holders have the right to require the Company to redeem the debentures
          on January 3, 2003 at a price of 112.418%, or upon the occurrence of a
          Fundamental  Change,  as defined in the  indenture  agreement,  at the
          prevailing redemption price. The Company may redeem the debentures, as
          a whole or in  part,  on or  after  December  29,  2000  initially  at
          108.324% and at increasing prices thereafter to 112.418% until January
          2, 2003 and 100%  thereafter.  Unless  the  debentures  are  redeemed,
          repaid or  converted  prior  thereto,  the  debentures  will mature on
          January  3,  2007 at their  principal  amount.  The  proceeds  of this
          issuance  are being  used for  general  corporate  purposes  including
          working capital.


                                       -8-


             Item 2. MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                            AND RESULTS OF OPERATIONS

Results of Operations
Third Quarter 1997 Compared to Third Quarter 1996

         Consolidated   worldwide   revenues  from  commission  and  fee  income
increased  18.2% in the third  quarter of 1997  compared to the third quarter of
1996.  Consolidated  domestic  revenues  increased 17.8% in the third quarter of
1997 to $402.3 million  compared to $341.6 million in the third quarter of 1996.
Consolidated international revenues increased 18.7% in the third quarter of 1997
to $344.5  million  compared  to $290.2  million  in the third  quarter of 1996.
Absent the effect of the net acquisitions of subsidiary  companies and movements
in  international  currency  exchange  rates,  consolidated  worldwide  revenues
increased  14.5% in the third  quarter of 1997 as compared to the same period in
1996.

         Operating  expenses  increased  16.6% in the third  quarter  of 1997 as
compared  to the  third  quarter  of  1996.  Excluding  the  effect  of the  net
acquisition  activity and movements in  international  currency  exchange  rates
mentioned  above,  operating  expenses  increased  14.5% over 1996 levels.  This
increase   reflects  normal  salary  increases  and  growth  in  client  service
expenditures to support the increased revenue base.


                                      - 9 -


                 MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                      AND RESULTS OF OPERATIONS (CONTINUED)

         Net interest expense  increased by $2.4 million in the third quarter of
1997 as compared to the same period in 1996.  This increase  primarily  reflects
higher average  borrowings  during the quarter partially offset by the effect of
higher average  amounts of cash and marketable  securities  invested  during the
quarter.

         Pretax  profit margin was 9.8% in the third quarter of 1997 as compared
to 8.7% in the same period in 1996.  Operating  margin,  which excludes interest
and dividend income and interest expense, was 10.7% in the third quarter of 1997
as compared to 9.4% in the same period in 1996.

         The effective income tax rate was 40.9% in the third quarter of 1997 as
compared to the effective income tax rate of 40.3% in the third quarter of 1996.
The  increase   primarily   reflects  higher  effective  tax  rates  at  certain
international subsidiaries.

         The increase in equity in affiliates  is indicative of greater  profits
earned by companies  in which the Company owns less than a 50% equity  interest,
partially offset by the conversion of certain affiliates into subsidiaries.  The
increase in minority  interest  expense is primarily due to greater  earnings by
companies  where  minority  interests  exist and additional  minority  interests
resulting from acquisitions.

         Net income  increased 28.7% in the third quarter of 1997 as compared to
the same period in 1996.  Absent the effect of net 


                                     - 10 -


                 MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                      AND RESULTS OF OPERATIONS (CONTINUED)

acquisitions and movements in international  currency exchange rates, net income
increased 17.3% in the third quarter of 1997 as compared to the third quarter of
1996.

Nine Months 1997 Compared to Nine Months 1996

     Consolidated  worldwide  commission and fee income  increased  18.0% in the
first  nine  months  of  1997  compared  to  the  first  nine  months  of  1996.
Consolidated  domestic  commission and fee income  increased  17.0% in the first
nine months of 1997 to $1,190.9 million compared to $1,017.8 million in the same
period in 1996. Consolidated  international  commission and fee income increased
19.1% in the first nine  months of 1997 to $1,038.9  million  compared to $872.0
million  in the  same  period  in  1996.  Absent  the  effect  of  movements  in
international  currency  exchange  rates  and  net  acquisitions  of  subsidiary
companies made subsequent to the third quarter of 1996,  consolidated  worldwide
commission  and fee  income  increased  13.4% in the first  nine  months of 1997
versus the first nine months of 1996.

     Operating  expenses  increased by 17.1% in the first nine months of 1997 as
compared  to the same  period in 1996.  Excluding  the  effect of  movements  in
international  currency exchange rates and net acquisition  activity,  operating
expenses increased 13.3% over 1996 levels.

     Net interest expense  decreased by $0.5 million in the first nine months of
1997 as compared to the same period in 1996.  This decrease  primarily  reflects
higher average  amounts 


                                      -11-



                 MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                      AND RESULTS OF OPERATIONS (CONTINUED)

of cash and  marketable  securities  invested  during the  period  offset by the
effect of higher average borrowings during the period.

     Pretax  profit  margin  for the  first  nine  months  of 1997 was  11.7% as
compared to 10.9% in the same period in 1996.  Operating margin,  which excludes
interest and dividend income and interest  expense,  was 12.4% in the first nine
months of 1997 as compared to 11.7% in the same period in 1996.

     The effective income tax rate was 40.7% in the first nine months of 1997 as
compared to the  effective  income tax rate of 40.4% in the first nine months of
1996.  The increase  primarily  reflects  higher  effective tax rates at certain
international subsidiaries.

     The  increase in equity in  affiliates  is  indicative  of greater  profits
earned by companies  in which the Company owns less than a 50% equity  interest,
partially offset by the conversion of certain affiliates into subsidiaries.  The
increase in minority  interest  expense is primarily due to greater  earnings by
companies  where  minority  interests  exist and additional  minority  interests
resulting from acquisitions.

     Net income  increased 27.4% in the first nine months of 1997 as compared to
the same period in 1996.  Absent the effect of net acquisitions and movements in
international  currency  exchange rates, net income increased 18.3% in the first
nine months of 1997 as compared  to the same period in 1996.


                                      -12-


                 MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                      AND RESULTS OF OPERATIONS (CONTINUED)

Capital Resources and Liquidity

         Cash and cash  equivalents  at September  30, 1997  decreased to $238.3
million  from $510.3  million at December  31, 1996.  The  relationship  between
payables to the media and suppliers and receivables  from clients,  at September
30, 1997, is consistent with seasonal and industry norms.

         The Company maintains  relationships  with a number of banks worldwide,
which have extended unsecured committed lines of credit in amounts sufficient to
meet the Company's  cash needs.  At September  30, 1997,  the Company had $572.0
million  in such  unsecured  committed  lines of credit,  comprised  of a $360.0
million revolving credit agreement expiring June 30, 2001, and $212.0 million in
lines of credit, principally outside of the United States. Of the $572.0 million
in unsecured committed lines, $248.5 million remained available at September 30,
1997.

         On  January  3,  1997,  the  Company  issued   $218,500,000   of  4.25%
Convertible  Subordinated  Debentures  with a scheduled  maturity  in 2007.  The
debentures  are  convertible  into common  stock of the Company at a  conversion
price of $63.00 per share  subject to adjustment  in certain  events.  Debenture
holders  have the right to  require  the  Company to redeem  the  debentures  on
January 3, 2003 at a price of 112.418%,  or upon the occurrence of a Fundamental
Change,  as defined in the indenture  agreement,  at the  prevailing  redemption
price. The Company may redeem the debentures, as a whole or in part, on or after
December 29, 2000 initially at 108.324% and at increasing  prices  thereafter to


                                      -13-


                 MANAGEMENT'S DISCUSSION OF FINANCIAL CONDITION
                      AND RESULTS OF OPERATIONS (CONTINUED)

112.418%  until January 2, 2003 and 100%  thereafter.  Unless the debentures are
redeemed,  repaid or converted  prior  thereto,  the  debentures  will mature on
January 3, 2007 at their  principal  amount.  The proceeds of this  issuance are
being used for general corporate purposes including working capital.

         Management  believes  the  aggregate  lines of credit  available to the
Company  plus cash  flows  from  operations  will be  adequate  to  support  its
anticipated requirements.


                                      -14-



                           PART II. OTHER INFORMATION

Item 6.  Exhibits

         Exhibit Number                          Description of Exhibit
         --------------                          ----------------------     
              27                                 Financial Data Schedule (filed
                                                 in electronic format only)

SIGNATURES

         Pursuant to the  requirements  of the Securities  Exchange Act of 1934,
the  registrant  has duly  caused  this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                                 Omnicom Group Inc.
                                                 (Registrant)

Date  November 11, 1997                          /s/  Fred J. Meyer
    --------------------                         ------------------
                                                 Fred J. Meyer
                                                 Chief Financial Officer
                                                 (Principal Financial Officer)

Date  November 11, 1997                          /s/  Jonathan E. Ramsden
    --------------------                         ------------------------
                                                 Jonathan E. Ramsden
                                                 Controller
                                                 (Principal Accounting Officer)
          

                                      -15-