Third Quarter 2019 Results

2019 vs. 2018 Non-GAAP Financial Measures - Excluding Impact of Third Quarter 2018 Dispositions, Repositioning Actions and the 2017 Tax Act Net Income - Omnicom Group Inc. Diluted Shares (millions) Earnings per Share - Diluted Dividends Declared Per Common Share $ ᏌᏊ Ꭿ OmnicomGroup $ 2019 Third Quarter 2018 (a) 290.2 $ 219.4 1.32 0.65 LA 298.9 $ 225.9 Non-GAAP 2018 Adjusted (a) 1.32 $ 0.60 $ (a) Please refer to Q3 2018 QTD dispositions, repositioning and tax adjustment footnote on page 2 and additional information on page 28. The above table, along with the table on page 5, identifies the U.S. GAAP financial measures of Operating Profit, Income Tax Expense, Income from Equity Method Investments, Net Income Attributed to Noncontrolling Interests and Net Income - Omnicom Group Inc. and Earnings per Share - Diluted as reported, as well as the non-GAAP amounts excluding the impact of the net gain recognized on dispositions of certain subsidiaries, certain repositioning actions and the revision of the provisional income tax expense amounts recorded in connection with the enactment of the 2017 Tax Act, in the column entitled "Non-GAAP 2018 Adjusted" for the three months ended September 30, 2018. We believe that the amounts presented in the "Non-GAAP 2018 Adjusted" column are useful measures for investors to understand the impact these items had on our reported results. Non-GAAP financial measures should not be considered in isolation from, or as a substitute for, financial information presented in compliance with U.S. GAAP. Non-GAAP financial measures reported by us may not be comparable to similarly titled amounts reported by other companies. Please see page 33 for the definition of this measure and pages 28, 30 and 31 for the reconciliation of non-GAAP financial measures, which reconciles the reported U.S. GAAP financial measures to the non-GAAP amounts presented above. 280.7 October 15, 2019 225.9 1.24 0.60 6

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