The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities, and they are not soliciting an offer to buy these securities, in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 6, 2012

Preliminary Prospectus Supplement
(to prospectus dated February 22, 2012)

OMNICOM GROUP INC.
OMNICOM CAPITAL INC.

3.625% Senior Notes due 2022

Issue price:

Interest payable May 1 and November 1

The notes will bear interest at the rate of 3.625% per annum, accruing from April 23, 2012. The public offering price of the notes will include accrued interest from April 23, 2012 to the date of issuance of such notes. Interest on the notes will be payable on May 1 and November 1 of each year, beginning on November 1, 2012. We may redeem all or part of the notes at any time by paying a specified make-whole premium as described on page S-10 of this prospectus supplement and page 9 of the accompanying prospectus.

The notes will be the joint and several unsecured and unsubordinated obligations of Omnicom Group Inc. and Omnicom Capital Inc. and will rank equal in right of payment to all of their respective existing and future unsecured senior indebtedness.

Omnicom Capital Inc.’s obligations in respect of the notes will be guaranteed by Omnicom Group Inc. The unconditional guarantee will be an unsecured and unsubordinated obligation of Omnicom Group Inc. and will rank equal in right of payment to all existing and future unsecured senior indebtedness of Omnicom Group Inc.

There is currently no active public market for the notes. The notes will not be listed on any securities exchange or included in any authorized quotation system.

Investing in the notes involves risks. See “Risk Factors” beginning on page S-5 of this prospectus supplement and under “Item 1A. Risk Factors” in Omnicom Group Inc.’s Annual Report on Form 10-K for the year ended December 31, 2011, which is incorporated by reference in this prospectus supplement and the accompanying prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined whether this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

	Price to Public(1)	Underwriting Discount	Proceeds, Before Expenses
Per note	%	%	%
Total	$	$	$

(1)

Plus accrued interest from April 23, 2012 (totaling $ per note), the date of the original issuance of the $750,000,000 of 3.625% Senior Notes due 2022, to the date of issuance of the notes offered hereby, which is expected to be August , 2012.

The notes are expected to be delivered through the book-entry facilities of The Depository Trust Company and its participants, including Euroclear Bank S.A./N.V. and Clearstream Banking, société anonyme, on or about , 2012.

Joint Book-Running Managers

TABLE OF CONTENTS

Prospectus Supplement

	Page
Special Note on Forward-Looking Statements	S-i
Summary	S-1
Risk Factors	S-5
Ratio of Earnings to Fixed Charges	S-6
Use of Proceeds	S-6
Capitalization	S-7
Selected Financial Data	S-8
Description of Notes	S-9
Material United States Federal Income Tax Considerations	S-13
Underwriting	S-18
Legal Matters	S-20
Independent Registered Public Accounting Firm	S-20
Where You Can Find More Information; Incorporation By Reference	S-21

Prospectus

	Page
The Company	1
About This Prospectus	2
Where You Can Find More Information; Incorporation By Reference	2
Special Note on Forward-Looking Statements	3
Use of Proceeds	3
Ratio of Earnings to Fixed Charges	4
Description of Omnicom Group Inc. Common Stock	4
Description of Omnicom Group Inc. Preferred Stock	5
Description of Debt Securities	7
Description of Omnicom Group Inc. Subscription Rights	13
Description of Omnicom Group Inc. Warrants	14
Plan of Distribution	15
Validity of Securities	15
Independent Registered Public Accounting Firm	15

This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, utilizing the “shelf” registration process. Under this shelf registration process, we may, from time to time, sell the securities described in the accompanying prospectus in one or more offerings. You should read both this prospectus supplement and the accompanying prospectus together with the additional information described under the heading “Where You Can Find More Information; Incorporation by Reference” on page S-21 of this prospectus supplement and on page 2 of the accompanying prospectus.

We have not, and the underwriters and their affiliates have not, authorized anyone to provide you with any information or to make any representation not contained in or incorporated by reference into this prospectus supplement. We do not, and the underwriters and their affiliates do not, take any responsibility for, and can provide no assurances as to, the reliability of any information that others may provide you. We are not, and the underwriters and their affiliates are not, making an offer to sell, or seeking offers to buy, these securities in any jurisdiction where the offer or sale is not permitted. The information contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed since that date.

SPECIAL NOTE ON FORWARD-LOOKING STATEMENTS

Certain of the statements in this prospectus supplement and the accompanying prospectus constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. In addition, from time to time, we or our representatives have made or may make forward-looking statements, orally or in writing. These statements relate to future events or future financial performance and involve known and unknown risks and other factors that may cause our actual or our industry’s results, levels of activity or achievement to be materially different from those expressed or implied by any forward-looking statements. These risks and uncertainties, including those resulting from specific factors identified under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the year ended December 31, 2011 and our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2012 and June 30, 2012 (as amended), include, but are not limited to, our future financial position and results of operations, global economic conditions and conditions in the credit markets, losses on media purchases and production costs incurred on behalf of clients, reductions in client spending and/or a slowdown in client payments, competitive factors, changes in client communication requirements, managing conflicts of interest, the hiring and retention of personnel, maintaining a highly skilled workforce, our ability to attract new clients and retain existing clients, reliance on information technology systems, changes in government regulations impacting our advertising and marketing strategies, risks associated with assumptions we make in connection with our critical accounting estimates and legal proceedings, and our international operations, which are subject to the risks of currency fluctuations and foreign exchange controls. In some cases, forward-looking statements can be identified by terminology such as “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of those terms or other comparable terminology. These statements are our present expectations. Actual events or results may differ. We undertake no obligation to update or revise any forward-looking statement, except as required by law.

SUMMARY

The following summary is qualified in its entirety by the more detailed information included elsewhere or incorporated by reference into this prospectus supplement and the accompanying prospectus. Because this is a summary, it may not contain all the information that may be important to you. You should read this prospectus supplement and the accompanying prospectus, as well as the information incorporated by reference, in their entirety before making an investment decision. When used in this prospectus supplement, the term “Omnicom Group” refers to Omnicom Group Inc. together with its consolidated subsidiaries, the term “Omnicom Group Inc.” refers to only Omnicom Group Inc. and not its subsidiaries, the term “Omnicom Capital” refers only to Omnicom Capital Inc., and the terms “Issuers,” “we,” “us,” and “our” refer collectively to Omnicom Group Inc. and Omnicom Capital, in each case, unless otherwise specified, as in the section captioned “Description of Notes” beginning on page S-9 of this prospectus supplement or “Description of Debt Securities” beginning on page 7 of the accompanying prospectus, except as the context requires and to reflect the merger of Omnicom Finance Inc. with and into Omnicom Group Inc. described below.

Omnicom Group Inc.

Omnicom Group is a leading global marketing and corporate communications company. Omnicom Group’s branded networks and numerous specialty firms provide advertising, strategic media planning and buying, digital and interactive marketing, direct and promotional marketing, public relations and other specialty communications services to over 5,000 clients in more than 100 countries. Omnicom Group’s revenue is diversified across a number of industries. Specifically, Omnicom Group’s revenue for the six months ended June 30, 2012, classified by industry sector, expressed as a percentage of total revenue from these clients, is as follows: Food and Beverage: 14%, Pharmaceutical and Healthcare: 10%, Consumer Products: 10%, Technology: 9%, Financial Services: 9%, Auto: 8%, Retail: 7%, Travel and Entertainment: 6%, Telecom: 6% and Other: 21%.

Omnicom Group’s agencies operate in all major markets around the world and provide a comprehensive range of services, which we group into four fundamental disciplines: advertising, customer relationship management, or CRM, public relations and specialty communications. The services included in these categories are:


advertising	marketing research
brand consultancy	media planning and buying
corporate social responsibility consulting	mobile marketing
crisis communications	multi-cultural marketing
custom publishing	non-profit marketing
data analytics	organizational communications
database management	package design
direct marketing	product placement
entertainment marketing	promotional marketing
environmental design	public affairs
experiential marketing	public relations
field marketing	recruitment communications
financial / corporate business-to-business advertising	reputation consulting
graphic arts	retail marketing
healthcare communications	search engine marketing
instore design	social media marketing
interactive marketing	sports and event marketing
investor relations

Omnicom Group Inc. is incorporated in New York and is a holding company. Its principal corporate offices are located at 437 Madison Avenue, New York, NY 10022, One East Weaver Street, Greenwich, CT 06831 and 1800 N. Military Trail, Boca Raton, FL 33431. Its telephone numbers are (212) 415-3600, (203) 618-1500 and (561) 750-5122, respectively.

Omnicom Group Inc.’s common stock is traded on the New York Stock Exchange under the symbol “OMC.” For additional information regarding Omnicom Group’s business, see the Annual Report on Form 10-K for the year ended December 31, 2011, or the 2011 10-K, and other SEC filings made by Omnicom Group Inc., which are incorporated by reference into this prospectus supplement. Copies of these filings may be obtained as described under “Where You Can Find More Information; Incorporation by Reference” on page S-21 of this prospectus supplement.

Omnicom Capital Inc.

Omnicom Capital is a wholly owned direct subsidiary of Omnicom Group Inc. Omnicom Capital has no independent operations or subsidiaries. The sole function of Omnicom Capital is to provide funding for the operations of Omnicom Group Inc. and its operating subsidiaries by incurring debt and lending the proceeds to the operating subsidiaries. Its assets consist of the intercompany loans it makes or has made to Omnicom Group Inc.’s operating subsidiaries and the related interest receivables.

Omnicom Capital is incorporated in Connecticut. Its principal office is located at One East Weaver Street, Greenwich, CT 06831 and its telephone number is (203) 625-3000.

Recent Developments

The initial issuance of $750,000,000 of 3.625% Senior Notes due 2022, which we refer to as the “existing notes,” were co-issued by Omnicom Group Inc., and two of its wholly owned finance subsidiaries, Omnicom Capital Inc. and Omnicom Finance Inc., as co-obligors. On July 20, 2012, Omnicom Finance Inc. was merged with and into Omnicom Group Inc. Pursuant to the merger, Omnicom Group Inc. assumed Omnicom Finance Inc.’s obligations under the existing notes. Accordingly, Omnicom Finance Inc. is no longer a co-obligor of the existing notes and will not be a co-obligor of the notes.

The Offering

The summary below describes the principal terms of the notes. Some of the terms and conditions described below are subject to important limitations and exceptions. See “Description of Notes” in this prospectus supplement and “Description of Debt Securities” in the accompanying prospectus for a more detailed description of the terms and conditions of the notes.

Issuer	Omnicom Group Inc.

Co-Obligor	Omnicom Capital, a wholly owned subsidiary of Omnicom Group Inc., will also be jointly and severally liable. Omnicom Group Inc. will guarantee the obligations of Omnicom Capital.

Notes Offered	$ aggregate principal amount of 3.625% Senior Notes due 2022. The notes offered hereby are an additional issuance of, will be fully fungible with and form a single series with the $750,000,000 of our 3.625% Senior Notes due 2022 initially issued on April 23, 2012.

Notes Outstanding After Offering	$ aggregate principal amount of 3.625% Senior Notes due 2022.

Maturity	The notes will mature on May 1, 2022.

Interest Rate	The notes will bear interest from April 23, 2012 at a rate equal to 3.625% per year, payable semiannually.

Interest Payment Dates	May 1 and November 1 of each year, commencing November 1, 2012.

Ranking	The notes will be the joint and several unsecured and unsubordinated obligations of Omnicom Group Inc. and Omnicom Capital and will rank equal in right of payment to all of their respective existing and future unsecured senior indebtedness. The notes will effectively rank junior to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness.

	The notes may effectively rank junior to all liabilities of our operating subsidiaries depending on the amount of loans to the operating subsidiaries and security for those loans on a relevant determination date. See “Risk Factors — Omnicom Group Inc.’s Holding Company Structure May Result in Structural Subordination and May Affect the Issuers’ Ability to Make Payments on the Notes.” As of June 30, 2012, the operating subsidiaries of Omnicom Group Inc. had approximately $10.7 billion of outstanding liabilities, including trade payables but excluding intercompany liabilities and deferred revenue.

Denominations	The notes will be issued in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

Optional Redemption	The Issuers may redeem the notes, in whole or in part, at any time or from time to time, at the redemption price set forth in the accompanying prospectus under the heading “Description of Notes — Optional Redemption” on page S-10 of this prospectus supplement and page 9 of the accompanying prospectus, plus a make-whole spread of 30 basis points.

Certain Covenants	The indenture governing the notes contains covenants limiting our and our subsidiaries’ ability to, with certain exceptions:

	•	create certain liens; and

	•	consolidate or merge with, or convey, transfer or lease substantially all our assets to, another person.

	You should read “Description of Notes” on page S-9 in this prospectus supplement and “Description of Debt Securities” on page 7 of the accompanying prospectus for additional information on these covenants.

Use of Proceeds	The net proceeds we receive from the sale of the notes offered hereby, after deducting the underwriting discount and estimated offering expenses payable by us, will be approximately $ million. We intend to use the net proceeds from the sale of the notes offered hereby for general corporate purposes, which could include working capital expenditures, fixed asset expenditures, acquisitions, refinancing of other debt, repurchases of our common stock or other capital transactions.

Risk Factors	See “Risk Factors” beginning on page S-5 of this prospectus supplement and the section entitled “Item 1A. Risk Factors” in Omnicom Group Inc.’s 2011 10-K for important information regarding us and an investment in the notes.

Further Issuances	We will have the ability to “reopen” the notes offered hereby and issue additional notes of that series having the same terms, except with respect to the payment of interest accruing prior to the issue date of such further notes or except for the first payment of interest following the issue date of such further notes.

Governing Law	The indenture will be governed by, and construed in accordance with, the laws of the State of New York.

RISK FACTORS

In considering whether to purchase notes, you should carefully consider all of the information contained in or incorporated by reference in this prospectus supplement and the accompanying prospectus, including but not limited to Omnicom Group Inc.’s 2011 10-K and other information which may be incorporated by reference into this prospectus supplement and the accompanying prospectus as provided under “Where You Can Find More Information; Incorporation by Reference.” Our ability to achieve and maintain profitability and our ability to continue to fund our operations on an on-going basis will depend on a number of factors, some of which are beyond our control. In addition to the risk factors set forth below, you should carefully consider the information under “Special Note on Forward-Looking Statements” and the risk factors set forth under the caption “Risk Factors” contained in Item 1A of Omnicom Group Inc.’s 2011 10-K.

Omnicom Group Inc.’s Holding Company Structure May Result in Structural Subordination and May Affect the Issuers’ Ability to Make Payments on the Notes

The notes are the joint and several obligations exclusively of the Issuers. Omnicom Group Inc. is a holding company and, accordingly, substantially all of its operations are conducted through its operating subsidiaries. Omnicom Capital is a wholly owned subsidiary of Omnicom Group Inc. Its assets consist of the intercompany loans it makes or has made to Omnicom Group Inc.’s operating subsidiaries and the related interest receivables. As a result, the Issuers’ cash flow and their ability to make payments on their respective debt, including the notes, are dependent upon the earnings of these operating subsidiaries. Omnicom Group Inc. is dependent on the distribution of earnings, loans or other payments by the operating subsidiaries to it to service its obligations in respect of the notes and its other debt. In addition, to service debt, Omnicom Capital, as a finance subsidiary, is also dependent on the earnings of the operating subsidiaries, the sale of certain assets of the operating subsidiaries and ability of the operating subsidiaries to repay principal and interest on the intercompany loans.

Omnicom Group Inc.’s operating subsidiaries are separate and distinct legal entities. These subsidiaries have no obligation to pay any amounts due on the notes or to provide the Issuers with funds for their respective payment obligations, whether by dividends, distributions, repayment or making of loans or other payments. In addition, any payment or repayment of dividends, distributions, loans or advances by these operating subsidiaries to the Issuers could be subject to legal or contractual restrictions. Payments to the Issuers by the operating subsidiaries will also be contingent upon the operating subsidiaries’ earnings and business considerations.

Because of this structure the claims of creditors of Omnicom Group Inc.’s operating subsidiaries will have a priority over the equity rights of Omnicom Group Inc. and the rights of its creditors, including the holders of notes, to participate in the assets of the subsidiary upon the subsidiary’s liquidation or reorganization. Although Omnicom Capital’s loans to the operating subsidiaries are secured by the assets of those subsidiaries, the rights of Omnicom Capital and its respective creditors, including holders of the notes, to participate in the assets of the operating subsidiaries will depend upon the amount of loans, and security for those loans, on the relevant date of determination. The amount of loans outstanding from Omnicom Capital to these operating subsidiaries, and the value of the collateral securing the loans, may not be sufficient to assure repayment in full to all of Omnicom Capital’s creditors. The loans or the security for such loans could also be invalidated in whole or in part in any liquidation or reorganization.

The Notes Do Not Restrict the Issuers’ Ability to Incur Additional Debt, Repurchase their Securities or to Take Other Actions that Could Negatively Impact Holders of the Notes

The Issuers are not restricted under the terms of the notes from incurring additional debt or repurchasing its securities. In addition, the indenture does not contain any covenants which require the Issuers to achieve or maintain any minimum financial results relating to its financial position or results of operations. The Issuer’s ability to recapitalize, incur additional debt and take a number of other

actions that are not limited by the terms of the notes could have the effect of diminishing its ability to make payments on the notes when due.

No assurance can be given as to the maintenance or liquidity of any trading market for the notes.

We do not intend to apply for listing of the notes on any securities exchange or for inclusion of the notes in any automated quotation system. Although we expect the notes offered hereby will be fungible with the $750,000,000 of our 3.625% Senior Notes due 2022 initially issued on April 23, 2012, for which a trading market currently exists, we cannot guarantee:

•

that such trading market will be maintained;

•

the liquidity of any trading market for the notes;

•

your ability to sell the notes at any time or at all; or

•

the price at which you would be able to sell the notes.

Liquidity of any market for the notes and future trading prices of the notes will depend on many factors, including:

•

prevailing interest rates;

•

our operating results;

•

credit rating or outlook changes; and

•

the market for similar securities

RATIO OF EARNINGS TO FIXED CHARGES

The following table shows the ratio of earnings to fixed charges of Omnicom Group Inc. for each of the five most recent fiscal years and for the six months ended June 30, 2012 and supersedes the Ratio of Earnings to Fixed Charges table on page 4 of the accompanying prospectus.


Six Months Ended	Year Ended December 31,
June 30, 2012	2011	2010	2009	2008	2007
7.01x	6.32x	6.12x	5.80x	6.70x	6.93x

The ratio of earnings to fixed charges is computed by dividing fixed charges into income before income taxes plus dividends from affiliates and fixed charges. Fixed charges consist of interest expense and that portion of net rental expense deemed representative of interest.

USE OF PROCEEDS

The net proceeds we receive from the sale of the notes offered hereby, after deducting the underwriting discount and estimated offering expenses payable by us, will be approximately $ million. We intend to use the net proceeds from the sale of the notes offered hereby for general corporate purposes, which could include working capital expenditures, fixed asset expenditures, acquisitions, refinancing of other debt, repurchases of our common stock or other capital transactions. Pending the application of the net proceeds, we may invest such net proceeds in short-term investment grade obligations.

CAPITALIZATION

The following table sets forth Omnicom Group Inc.’s actual consolidated cash, cash equivalents and short-term investments and capitalization, as of June 30, 2012, and as adjusted to reflect the issuance and sale of the notes offered hereby. You should read this table in conjunction with Omnicom Group Inc.’s financial statements and related notes and other financial and operating data included elsewhere in or incorporated by reference into this prospectus supplement and the accompanying prospectus.

		As of June 30, 2012 (Unaudited)
		Actual		As Adjusted
		(In millions)
Cash, cash equivalents and short-term investments	$	1,680.0		$
Short-term debt:
Current portion of debt	$	0.4		$
Short term borrowings		12.4
Total short-term debt	$	12.8		$
Long-term debt:
Long-term Notes Payable:
Senior Notes - due April 15, 2016	$	1,000.0		$
Senior Notes - due July 15, 2019		500.0
Senior Notes - due August 15, 2020		1,000.0
Senior Notes - due May 1, 2022		750.0
Notes offered hereby(1)		—
Other notes and loans		0.5
Unamortized premium (discount) on Senior Notes		(10.2	)
Deferred gain from termination of interest rate swap on
Senior Notes due 2016		26.8
		3,267.1
Less current portion		0.4
	$	3,266.7		$
Convertible Notes:
Convertible Notes – due July 31, 2032	$	252.7		$
Convertible Notes – due June 15, 2033		0.1
Convertible Notes – due July 1, 2038		406.6
		659.4
Less current portion		—
	$	659.4		$
Total long-term debt	$	3,926.1		$
Temporary equity – redeemable noncontrolling interests	$	208.7		$
Equity:
Shareholders’ Equity:
Preferred stock, $1.00 par value, 7,500,000 shares authorized,
none issued	$	—		$
Common stock, $0.15 par value, 1,000,000,000 shares authorized,
397,217,440 shares issued and 265,277,446 shares outstanding		59.6
Additional paid-in capital		952.8
Retained earnings		8,045.8
Accumulated other comprehensive income (loss)		(216.2	)
Treasury stock, at cost		(5,572.1	)
Total shareholders’ equity		3,269.9
Noncontrolling Interests		465.2
Total Equity	$	3,735.1		$
Total capitalization(2)	$	7,882.7		$

SELECTED FINANCIAL DATA

The following selected financial data should be read in conjunction with our unaudited financial statements, as well as “Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations,” in our Quarterly Report on Form 10-Q, as amended, for the quarterly period ended June 30, 2012, and our audited consolidated financial statements and related notes, as well as “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations,” in Omnicom Group Inc.’s 2011 10-K, all of which are incorporated herein by reference.

	Six months ended June 30, (Unaudited)				For the years ended December 31,
(In millions, except per share amounts)	2012		2011		2011		2010		2009		2008		2007
Revenue	$	6,868.2	$	6,638.8	$	13,872.5	$	12,542.5	$	11,720.7	$	13,359.9	$	12,694.0
Operating Income		868.9		810.3		1,671.1		1,460.2		1,374.9		1,689.4		1,659.1
Net Income –
Omnicom Group Inc.		487.3		477.0		952.6		827.7		793.0		1,000.3		975.7
Net Income Per Common Share –
Omnicom Group Inc.:
Basic		1.76		1.68		3.38		2.74		2.54		3.17		2.95
Diluted		1.74		1.65		3.33		2.70		2.53		3.14		2.93
Dividends Declared Per
Common Share		0.60		0.50		1.00		0.80		0.60		0.60		0.575

	As of June 30, (Unaudited)				As of December 31,
(In millions)	2012		2011		2011		2010		2009		2008		2007
Cash, Cash Equivalents and
Short-Term Investments	$	1,680.0	$	1,003.3	$	1,805.0	$	2,300.0	$	1,594.8	$	1,112.4	$	1,841.0
Total Assets		20,106.5		19,156.7		20,505.4		19,566.1		17,920.7		17,318.4		19,271.7
Long-Term Obligations:
Long-Term Notes Payable		3,266.7		2,488.0		2,523.5		2,465.1		1,494.6		1,012.8		1,013.2
Convertible Debt		659.4		659.4		659.4		659.5		726.0		2,041.5		2,041.5
Other Long-Term Liabilities		627.2		594.2		602.0		576.5		462.0		444.4		481.2
Total Shareholders’ Equity		3,269.9		3,554.3		3,504.3		3,580.5		4,194.8		3,522.8		4,091.7

Effective January 1, 2009, we retrospectively adopted new accounting standards included in the FASB Accounting Standards Codification, or FASB ASC, Topic 260, Earnings Per Share, with respect to allocating earnings to participating securities in applying the two-class method of calculating earnings per share. Net Income Per Common Share - Omnicom Group Inc. amounts for 2008 and 2007 have been restated in accordance with the new accounting standard.

DESCRIPTION OF NOTES

Set forth below is a description of the specific terms of the notes. This description supplements, and should be read together with, the description of the general terms and provisions of the debt securities, including the notes, set forth in the accompanying base prospectus under the caption “Description of Debt Securities.” The following description does not purport to be complete and is subject to, and is qualified in its entirety by reference to, the description of senior debt securities in the base prospectus and the senior indenture. If the description of the notes in this prospectus supplement differs from the description of senior debt securities in the base prospectus, the description of the notes in this prospectus supplement supersedes the description of debt securities in the base prospectus. When used in this section, the term “Issuers” refers solely to Omnicom Group Inc. and Omnicom Capital and not to any of their respective subsidiaries.

The notes offered hereby are an additional issuance of, will be fully fungible with and form a single series with the $750,000,000 of our 3.625% Senior Notes due 2022 initially issued on April 23, 2012. The notes will have the same CUSIP number assigned to such previously issued notes. On completion of this offering, $ million aggregate principal amount of our 3.625% Senior Notes due 2022 will be outstanding.

General

This offering of $ million aggregate principal amount of notes will constitute an additional issuance of the notes. The notes will be issued only in registered form, without coupons, in denominations of $2,000 and integral multiples of $1,000 in excess thereof. The notes will be the joint and several unsecured senior obligations of Omnicom Group Inc. and Omnicom Capital and, as such, will rank equal in right of payment with all other existing and future senior indebtedness of Omnicom Group Inc. and Omnicom Capital and senior in right of payment to all of their existing and future subordinated indebtedness. The notes may effectively rank junior to all liabilities of our operating subsidiaries depending on the amount of loans to the operating subsidiaries and security for those loans on a relevant determination date. See “Risk Factors — Omnicom Group Inc.’s Holding Company Structure May Result in Structural Subordination and May Affect the Issuers’ Ability to Make Payments on the Notes.” As of June 30 2012, on a pro forma basis after giving effect to the offering of the notes and the application of the estimated gross proceeds therefrom, the issuers would have had approximately $ billion aggregate principal amount of indebtedness outstanding. See “Use of Proceeds” and “Capitalization” in this prospectus supplement. Omnicom Capital’s obligations in respect of the notes are guaranteed by Omnicom Group Inc. The unconditional guarantee is a senior unsecured obligation of Omnicom Group Inc. and ranks equal in right of payment to all existing and future senior unsecured indebtedness of Omnicom Group Inc.

The specific terms of the notes are set forth below:

•

Title: 3.625% Senior Notes due 2022

•

Initial principal amount being issued: $

•

Stated maturity date: May 1, 2022

•

Interest rate: 3.625%

•

Date interest starts accruing: April 23, 2012

•

Interest payment dates: May 1 and November 1

•

First interest payment date: November 1, 2012

•

Regular record dates for interest: April 15 and October 15

•

Computation of interest: Interest will be computed on the basis of a 360-day year consisting of twelve 30-day months.

•

Form of notes: The notes will be in the form of one or more global notes that the issuers will deposit with or on behalf of The Depository Trust Company (“DTC”).

•

Sinking fund: The notes will not be subject to any sinking fund.

•

Trustee: Deutsche Bank Trust Company Americas

Optional Redemption

The notes are redeemable, as a whole or in part, at the Issuers’ option, at any time or from time to time. The redemption price will be as described in the accompanying prospectus plus a make-whole spread of 30 basis points. See “— Optional Redemption” on page 9 in the accompanying prospectus.

Certain Covenants

The indenture does not contain any provisions that would limit the Issuer’s ability to incur indebtedness or that would afford holders of notes protection in the event of a sudden and significant decline in the credit quality or rating of Omnicom Group Inc. or a takeover, recapitalization or highly leveraged or similar transaction involving Omnicom Group Inc.

Limitation on Liens

Omnicom Group Inc. will not, and will not permit any of its Subsidiaries to, create or suffer to exist any Lien on or with respect to any of Omnicom Group Inc.’s properties, whether now owned or hereafter acquired, to secure any Debt of Omnicom Group Inc., any direct or indirect subsidiary or any other Person, or to assign or permit any of its Subsidiaries to assign, without securing the notes equally and ratably with such Debt to which such Liens relate for so long as such Debt shall be so secured, other than:

•

Permitted Liens;

•

purchase money Liens upon or in any real property or equipment acquired or held by Omnicom Group Inc. or any Subsidiary in the ordinary course of business to secure the purchase price of such property or equipment or to secure Debt incurred solely for the purpose of financing the acquisition of such property or equipment, or Liens existing on such property or equipment at the time of its acquisition (other than any such Liens created in contemplation of such acquisition that were not incurred to finance the acquisition of such property) or extensions, renewals or replacements of any of the foregoing for the same or a lesser amount, provided, however, that no such Lien shall extend to or cover any properties of any character other than the real property or equipment being acquired and fixed improvements thereon or accessions thereto, and no such extension, renewal or replacement shall extend to or cover any properties not theretofore subject to the Lien being extended, renewed or replaced;

•

Liens existing on the date of this prospectus supplement;

•

Liens on property of a Person existing at the time such Person is merged into, consolidated with, or acquired by Omnicom Group Inc. or any Subsidiary of Omnicom Group Inc. or becomes a Subsidiary of Omnicom Group Inc.; provided that such Liens were not created in contemplation of such merger, consolidation or acquisition and do not extend to any assets other than those of the Person so merged into or consolidated with the Omnicom Group Inc. or such Subsidiary or acquired by Omnicom Group Inc. or such Subsidiary;

•

Liens granted by Subsidiaries of Omnicom Group Inc. (other than Omnicom Capital Inc.) to secure Debt owed to Omnicom Group Inc. or a wholly owned Subsidiary of Omnicom Group Inc.;

•

Liens arising out of judgment, decree or order of court being contested in good faith by appropriate proceedings, provided that adequate reserves with respect thereto are maintained on the books of Omnicom Group Inc. or the books of its Subsidiaries, as the case may be, in conformity with U.S. GAAP;

•

Debt of a Person existing at the time such Person is merged into or consolidated with Omnicom Group Inc. or becomes a Subsidiary of Omnicom Group Inc. provided that such Debt was not created in contemplation of such merger, consolidation or acquisition and provided further that the aggregate principal amount of such Debt shall not exceed $50,000,000 at any time outstanding;

•

Liens to secure any extension, renewal, refinancing or refunding (or successive extensions, renewals, refinancings or refundings), in whole or in part, of any Debt secured by Liens referred to above or Liens created in connection with any amendment, consent or waiver relating to such Debt, so long as such Lien does not extend to any other property, the amount of Debt secured is not increased (other than by the amount equal to any costs and expenses incurred in connection with any extension, renewal, refinancing or refunding) and the Debt so secured does not exceed the fair market value (as determined by our board of directors in good faith) of the assets subject to such Liens at the time of such extension, renewal, refinancing or refunding, or such amendment, consent or waiver, as the case may be;

•

Liens otherwise prohibited by this covenant, securing Debt, provided that the aggregate principal amount of such secured Debt shall not exceed 20% of the Consolidated Net Worth of Omnicom Group Inc. and its Subsidiaries at any time.

Certain Definitions

Set forth below are certain defined terms used in this description of the notes:

“Consolidated Net Worth” means the consolidated net worth of Omnicom Group Inc., as determined in accordance with generally accepted accounting principles in the United States of America or U.S. GAAP.

“Debt” of any Person means, without duplication, (a) all indebtedness of such Person for borrowed money, (b) all obligations of such Person for the deferred purchase price of property or services (other than earn-out payment obligations of such Person in connection with the purchase of property or services to the extent they are still contingent), (c) all obligations of such Person evidenced by notes, bonds, debentures or other similar instruments, (d) all obligations of such Person created or arising under any conditional sale or other title retention agreement with respect to property acquired by such Person (even though the rights and remedies of the seller or lender under such agreement in the event of default are limited to repossession or sale of such property), (e) all obligations of such Person as lessee under leases to the extent that such leases have been or should be, in accordance with U.S. GAAP, recorded as capital leases, (f) all obligations, contingent or otherwise, of such Person in respect of acceptances, letters of credit or similar extensions of credit, (g) all obligations of such Person in respect of Hedge Agreements, (h) all Debt of others referred to in clauses (a) through (g) above or clause (i) below and other payment obligations guaranteed directly or indirectly in any manner by such Person, or in effect guaranteed directly or indirectly by such Person through an agreement (1) to pay or purchase such Debt or to advance or supply funds for the payment or purchase of such Debt, (2) to purchase, sell or lease (as lessee or lessor) property, or to purchase or sell services, primarily for the purpose of enabling the debtor to make payment of such Debt or to assure the holder of such Debt against loss, (3) to supply funds to or in any other manner invest in the debtor (including any agreement to pay for property or services irrespective of whether such property is received or such services are rendered) or (4) otherwise to assure a creditor against loss, and (i) all Debt referred to in clauses (a) through (h) above secured by (or for which the holder of such Debt has an existing right, contingent or otherwise, to be secured by) any Lien on property (including, without limitation, accounts and contract rights) owned by such Person, even though such Person has not assumed or become liable for the payment of such Debt.

“Hedge Agreements” means interest rate swap, cap or collar agreements, interest rate future or option contracts, currency swap agreements, currency future or option contracts and other similar agreements.

“Lien” means any lien, security interest or other charge or encumbrance of any kind, or any other type of preferential arrangement intended to provide security for the payment or performance of an obligation, including, without limitation, the lien or retained security title of a conditional vendor and any easement, right of way or other encumbrance on title to real property.

“Permitted Liens” means such of the following as to which no enforcement, collection, execution, levy or foreclosure proceeding shall have been commenced: (a) Liens for taxes, assessments and governmental charges or levies to the extent not yet due and payable, or being contested in good faith by appropriate proceedings; (b) Liens imposed by law, such as materialmen’s, mechanics’, carriers’, workmen’s and repairmen’s Liens and other similar Liens arising in the ordinary course of business securing obligations that are not overdue for a period of more than 30 days or that are being contested in good faith and by appropriate proceedings that prevent the forfeiture or sale of the asset subject to such Lien; (c) pledges or deposits to secure obligations under workers’ compensation laws or similar legislation or to secure public or statutory obligations or, in any such case, to secure reimbursement obligations under letters of credit or bonds issued to support such obligations; and (d) easements, rights of way and other encumbrances on title to real property that do not render title to the property encumbered thereby unmarketable or materially adversely affect the use of such property for its present purposes.

“Person” means any individual, corporation, partnership, joint venture, association, limited liability company, joint-stock company, trust, unincorporated organization or government or any agency or political subdivision thereof.

“Subsidiary” of any Person means any corporation, partnership, joint venture, limited liability company, trust or estate of which (or in which) more than 50% of (a) the issued and outstanding voting stock of such Person, (b) the interest in the capital or profits of such limited liability company, partnership or joint venture or (c) the beneficial interest in such trust or estate is at the time directly or indirectly owned or controlled by such Person, by such Person and one or more of its other subsidiaries or by one or more of such Person’s other subsidiaries.

Book-Entry Notes

The notes will be issued in the form of one or more global securities in definitive, fully registered form, without interest coupons. Each global security will be deposited with the trustee, as custodian for, and registered in the name of, a nominee of DTC, as depositary and will be held through the book-entry system of DTC and its participants, including Euroclear and Clearstream. See “Description of Debt Securities — Book-Entry Procedures and Settlement” in the accompanying base prospectus for a description of registered global securities held in book entry form.

MATERIAL UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

The following discussion sets forth a summary of certain U.S. federal income tax considerations relating to the purchase, ownership and disposition of the notes.

This summary:

•

does not purport to be a complete analysis of all of the potential tax consequences that may be important to an investor based on the investor’s particular tax situation;

•

is based on the existing provisions of the Internal Revenue Code, or IRC, the existing applicable federal income tax regulations promulgated or proposed under the IRC, or the “Treasury Regulations,” judicial authority and current administrative rulings and practice, all of which are subject to change, possibly with retroactive effect, and which are subject to differing interpretations;

•

is applicable only to initial beneficial owners of notes who purchase notes in this offering at the price to the public shown on the front cover of this prospectus supplement and will hold their notes as “capital assets,” within the meaning of Section 1221 of the IRC, and does not discuss the tax consequences applicable to subsequent purchasers of the notes;

•

does not address tax consequences applicable to particular holders in light of their circumstances, including but not limited to:

•

holders subject to special tax rules, such as holders subject to the alternative minimum tax, banks, insurance companies, financial institutions, tax-exempt organizations, pension funds, regulated investment companies, real estate investment trusts, certain U.S. expatriates, dealers in securities or currencies, traders in securities that elect to use a mark to market method of accounting for their securities holdings and partnerships or other pass through entities;

•

U.S. holders (as defined below) whose “functional currency” is not the U.S. dollar;

•

persons holding the notes as a position in a hedging or constructive sale transaction, “straddle,” “conversion” or other integrated transaction for U.S. federal income tax purposes; and

•

non-U.S. holders (as defined below) subject to special rules under the IRC, such as “controlled foreign corporations” and “passive foreign investment companies;”

•

does not discuss any state, local or non-U.S. taxes and any U.S. federal tax other than the income tax, including but not limited to, the U.S. federal gift tax and estate tax; and

•

does not discuss any reporting requirements of or other consequences under the Treasury Regulations relating to certain tax shelter transactions.

We intend to treat the issuance of the notes pursuant to this prospectus supplement as part of the same issue as the 3.625% Senior Notes issued on April 23, 2012 for U.S. federal income tax purposes. If the issuance of the notes is so treated, the notes will have the same issue date, the same issue price and the same adjusted issue price as the existing notes for U.S. federal income tax purposes. The remainder of this discussion assumes that the notes will be treated as a part of the same issue as the existing notes.

A portion of the purchase price of the notes is attributable to the amount of interest accrued prior to the date the notes are acquired in this offering, or the pre-issuance accrued interest. Because the issue price of the notes as determined for U.S. federal income tax purposes excludes any pre-issuance accrued interest, a portion of the stated interest payment on November 1, 2012 on the notes equal to any pre-issuance accrued interest will be treated as a return of such pre-issuance accrued interest and will not be taxable as interest on the notes. The remainder of this discussion assumes that the notes will be so treated, and all references to stated interest in the remainder of this discussion exclude reference to pre-issuance accrued interest.

Prospective investors are urged to consult their own tax advisors regarding the U.S. federal, state and local and non-U.S. tax consequences of the purchase, ownership, sale and other disposition of the notes. We have not sought and will not seek any rulings from the Internal Revenue Service, or IRS, with respect to any matter discussed herein. The IRS may not agree with the statements made and conclusions reached in the discussion and may successfully assert a contrary position.

THIS SUMMARY IS NOT INTENDED AS TAX ADVICE. WE URGE PROSPECTIVE INVESTORS IN THE NOTES TO CONSULT THEIR OWN TAX ADVISORS REGARDING THE U.S. FEDERAL, STATE, LOCAL AND NON-UNITED STATES INCOME AND OTHER TAX CONSEQUENCES OF INVESTING IN THE NOTES.

As used in this summary, the term “U.S. holder” means a beneficial owner of a note that is, for U.S. federal income tax purposes:

•

a citizen or resident of the United States;

•

a corporation or other entity taxable as a corporation that is organized in or under the laws of the United States, any state thereof or the District of Columbia;

•

an estate, the income of which is subject to U.S. federal income taxation regardless of its source; or

•

a trust, if (1) a court within the United States is able to exercise primary supervision over the trust’s administration and one or more “United States persons,” as defined in Section 7701(a)(30) of the IRC, have the authority to control all substantial decisions of the trust or (2) in respect of a trust that is subject to certain grandfather rules, a valid election is in effect in respect of such trust.

The term “non-U.S. holder” means any beneficial owner of a note that is neither a U.S. holder nor a partnership or other entity or arrangement treated as a partnership for U.S. federal income tax purposes.

If a partnership, including any entity or arrangement treated as a partnership for U.S. federal income tax purposes, holds notes, then the tax treatment of a partner in such partnership will generally depend on the status of the partner and the activities of the partnership. Such partners and partnerships are urged to consult with their own tax advisors concerning the U.S. federal income tax consequences of the purchase, ownership and disposition of the notes.

U.S. Holders

This discussion is a summary of the U.S. federal income tax consequences that will apply to U.S. holders. Certain U.S. federal income tax consequences applicable to non-U.S. holders are described under the heading “—Non-U.S. Holders” below.

Stated Interest

Stated interest on the notes generally will be treated as “qualified stated interest” for U.S. federal income tax purposes and taxable to a U.S. holder as ordinary interest income at the time it is paid or accrued in accordance with such holder’s regular method of accounting for U.S. federal income tax purposes.

If a U.S. holder purchases a note for an amount (excluding any amounts attributable to pre-issuance accrued interest, as discussed above) in excess of the sum of all amounts payable on the note (other than in respect of stated interest), such excess will be considered “amortizable bond premium.” For this purpose, in determining the sum of all amounts payable on the note, it will initially be assumed that we will exercise our rights to call the notes at a premium, and subsequent adjustments may be made if we do not in fact exercise our call rights. This assumption may eliminate, reduce or defer any amortizable deductions.

A U.S. holder may elect to reduce the amount required to be included in income each year with respect to interest on a note by the amount of amortizable bond premium allocable to that year, based on the note’s yield to maturity (and taking into account the foregoing assumptions). U.S. holders should consult their own tax advisors about these rules. If a U.S. holder makes the election to amortize bond premium, it will apply to all debt instruments (other than debt instruments the interest on which is excludible from gross income) that the U.S. holder holds at the beginning of the first taxable year to which the election applies or thereafter acquires, and the election may not be revoked without the consent of the IRS.

Sale, Exchange, Redemption, Retirement or other Taxable Disposition of Notes

Upon the sale, exchange, redemption, retirement or other taxable disposition of a note, a U.S. holder generally will recognize taxable gain or loss. The amount of such gain or loss generally will be measured by the difference, if any, between the amount realized on such disposition, except to the extent any amount realized is attributable to accrued but unpaid stated interest, which will be treated as such, and such holder’s adjusted tax basis in the sold, exchanged, redeemed, retired or disposed notes.

A U.S. holder’s adjusted tax basis in a note generally will equal such holder’s initial investment in such note (other than amounts attributable to pre-issuance accrued interest), decreased by the amount of any principal payments and other payments on the note that are not deemed to be qualified stated interest payments received by such holder and decreased by any amortizable bond premium previously deducted by such U.S. holder with respect to the note.

Gain or loss recognized on the disposition of a note generally will be capital gain or loss and, if the holder held the disposed note for more than one year at the time of disposition, long-term capital gain or loss. For non-corporate U.S. holders (including individuals), long-term capital gains currently are subject to preferential rates of taxation. Subject to certain exceptions, holders cannot use capital losses to offset their ordinary income. To the extent that the amount realized is attributable to accrued but unpaid interest, such amount will be taxable as interest, as described under the heading “—Stated Interest” above.

Medicare Tax

Legislation enacted in 2010 will require certain U.S. holders who are individuals, estates or trusts to pay a 3.8% Medicare tax on all or part of that holder’s “net investment income,” which includes, among other items, interest on, and capital gains from the sale or other taxable disposition of, the notes. This tax will apply to taxable years beginning after December 31, 2012. Prospective investors should consult their own tax advisors regarding the effect, if any, of this legislation on their investment in the notes.

Non-U.S. Holders

The following is a summary of certain U.S. federal income and withholding tax consequences generally applicable to non-U.S. holders. Non-U.S. holders are encouraged to consult their own tax advisors concerning the relevant U.S. federal, state and local and any non-U.S. tax consequences that may be relevant to their particular situations.

Interest

Payments made and accruals of interest on the notes to a non-U.S. holder generally will be exempt from U.S. federal income and withholding tax, provided that:

•

such payments are not effectively connected with the conduct by such non-U.S. holder of a trade or business within the United States (or, in the case of an applicable tax treaty, are not attributable to such non-U.S. Holder’s U.S. “permanent establishment” or “fixed base”);

•

the non-U.S. holder does not own, actually or constructively under applicable attribution rules, 10% or more of the total combined voting power of all classes of our stock entitled to vote; and

•

the non-U.S. holder provides its name and address and certifies, under penalty of perjury, on a properly executed and delivered IRS Form W-8BEN or other form, if applicable, that such holder is not a United States person for U.S. federal income tax purposes.

The certification described in the last clause above may be provided by a securities clearing organization, bank or other financial institution that holds customers’ securities in the ordinary course of its trade or business. This certification may also be provided by a qualified intermediary on behalf of one or more beneficial owners or other intermediaries, provided that such qualified intermediary has entered into a withholding agreement with the IRS and other conditions are satisfied.

A non-U.S. holder that is not exempt from tax under these rules generally will be subject to U.S. federal withholding tax at a gross rate of 30%, or such lower rate if provided in an applicable income tax treaty, unless the interest is effectively connected with the conduct by the non-U.S. holder of a trade or business within the United States (or, if provided in an applicable income tax treaty, is attributable to a U.S. “permanent establishment” or “fixed base”) and the non-U.S. holder so certifies under penalty of perjury on a properly executed and delivered IRS Form W-8ECI or other applicable form. In such case, interest will be subject to U.S. federal income tax based on such non-U.S. holder’s net effectively connected income generally in a similar manner as if it were received by a U.S. holder (but without regard to the Medicare tax described above). Corporate non-U.S. holders receiving interest income that is effectively connected with the conduct of a trade or business within the United States may also be subject to an additional “branch profits” tax at a 30% rate or a lower rate if specified by an applicable income tax treaty.

Non-U.S. holders should consult applicable income tax treaties, which may provide reduced rates of or an exemption from U.S. federal income or withholding tax and branch profits tax. Non-U.S. holders will be required to satisfy certification requirements in order to claim a reduction of or exemption from withholding tax pursuant to any applicable income tax treaties. A non-U.S. holder may meet these requirements by providing an IRS Form W-8BEN or appropriate substitute to us or our agent, whereby the non-U.S. holder certifies under penalty of perjury that it is entitled to treaty benefits and provides such non-U.S. holder’s U.S. taxpayer identification number.

Sale, Exchange, Redemption or Other Taxable Disposition of Notes

Subject to the discussion below concerning backup withholding, a non-U.S. holder generally will not be subject to U.S. federal income or withholding tax on any gain recognized upon the sale, exchange, redemption or other taxable disposition of a note unless:

•

that gain is effectively connected with the conduct of a trade or business within the United States by the non-U.S. holder (or, if provided in an applicable income tax treaty, is attributable to a U.S. “permanent establishment” or “fixed base”); or

•

in the case of a non-U.S. holder who is a nonresident alien individual and holds the notes as a capital asset, such holder is present in the United States for at least 183 days in the tax year of the sale or other disposition and certain other conditions exist.

A non-U.S. holder described in the first bullet point above will generally be required to pay U.S. federal income tax on the net gain derived from the sale or other disposition of the notes, except as otherwise required by an applicable tax treaty. If such non-U.S. holder is a corporation, then it may also be subject to an additional “branch profits” tax at a 30% rate or a lower rate if so specified by an applicable income tax treaty. A non-U.S. holder described in the second bullet point above will generally be subject to tax at a gross rate of 30% on the excess of all of such holder’s U.S. source capital gains during the tax year over any U.S. source capital losses during such tax year, except as otherwise required by an applicable tax treaty. To the extent that the amount realized on any sale, exchange, redemption or other taxable disposition of the notes is attributable to accrued but unpaid interest, such amount will be taxable as such, as described under the heading “— Interest” above.

Information Reporting and Backup Withholding

U.S. Holders

Certain non-exempt U.S. holders will be subject to information reporting in respect of any payments that we may make or are made on our behalf on the notes and the proceeds of any sale or other disposition of the notes. In addition, backup withholding may apply, unless the U.S. holder supplies a taxpayer identification number and other information, certified under penalty of perjury, or otherwise establishes, in the manner prescribed by applicable law, an exemption from backup withholding. Backup withholding does not represent an additional income tax. Amounts withheld under the backup withholding rules are allowable as a refund or a credit against the U.S. holder’s federal income tax upon furnishing the required information on a timely basis to the IRS. Prospective U.S. holders should consult their own tax advisors concerning the application of information reporting and backup withholding rules.

Non-U.S. Holders

We will, where required, report to non-U.S. holders and to the IRS the amount of any principal and interest paid on the notes. Copies of these information returns may be made available under the provisions of a specific treaty or other agreement to the tax authorities of the country in which the non-U.S. holder resides or is organized.

Backup withholding tax will not apply to payments of interest with respect to which either the requisite certification that the non-U.S. holder is not a United States person for U.S. federal income tax purposes, as described above, has been received or an exemption has been otherwise established, provided that neither we nor our paying agent have actual knowledge or reason to know that the non-U.S. holder is a United States person for U.S. federal income tax purposes that is not an exempt recipient or that the conditions of any other exemption are not, in fact, satisfied.

Payments on the sale, exchange or other disposition of the notes effected through a foreign office of a broker to an offshore account maintained by a non-U.S. holder are generally not subject to information reporting or backup withholding. However, if the broker is a United States person, a “controlled foreign corporation,” a non-United States person 50% or more of whose gross income is effectively connected with trade or business within the United States for a specified three-year period, a foreign partnership with significant U.S. ownership or a U.S. branch of a foreign bank or insurance company, then information reporting will be required, unless the broker has documentary evidence in its records that the beneficial owner of the payment is not a United States person or is otherwise entitled to an exemption and the broker has neither actual knowledge nor a reason to know that the beneficial owner is not entitled to an exemption. Backup withholding will apply if the sale or other disposition is subject to information reporting and the broker has actual knowledge or reason to know that the beneficial owner is a United States person that is not an exempt recipient.

Information reporting and backup withholding will apply to payments effected at a U.S. office of any U.S. or foreign broker, unless the broker has documentary evidence in its records that the beneficial owner of the payment is not a United States person or is otherwise entitled to an exemption and the broker has no actual knowledge or reason to know that the beneficial owner is not entitled to an exemption.

Backup withholding does not represent an additional income tax. Amounts withheld from payments to a non-U.S. holder under the backup withholding rules may be credited against that holder’s U.S. federal income tax liability and may entitle that holder to a refund, provided that the required information is timely furnished to the IRS. Prospective non-U.S. holders should consult their own tax advisors concerning the application of information reporting and backup withholding rules.

UNDERWRITING

Under the terms and subject to the conditions contained in an underwriting agreement dated the date of this prospectus supplement, the underwriters named below, for whom J.P. Morgan Securities LLC and Citigroup Global Markets Inc. are acting as a representatives, have severally agreed to purchase, and Omnicom Group Inc. and Omnicom Capital have agreed to sell to them, severally, the principal amount of notes set forth opposite their names below:

Underwriters		Principal Amount of Notes
J.P. Morgan Securities LLC		$
Citigroup Global Markets Inc.
Total		$

The underwriters are offering the notes subject to their acceptance of the notes from us and subject to prior sale. The underwriting agreement provides that the obligations of the several underwriters to pay for and accept delivery of the notes offered by this prospectus supplement are subject to the approval of certain legal matters by counsel and to certain other conditions. The underwriters have agreed to purchase all of the notes offered by this prospectus supplement if any of the notes are purchased.

The underwriters initially propose to offer part of the notes directly to the public at the offering price set forth on the cover page of this prospectus supplement. In addition, the underwriters initially propose to offer part of the notes to certain dealers at a price that represents a concession not in excess of % of the principal amount of the notes. Any underwriter may allow, and any such dealer may reallow, a concession not in excess of % of the principal amount of the notes to certain other dealers. After the initial offering of the notes, the underwriters may from time to time vary the offering price and other selling terms.

The following table shows the underwriting discount that we will pay to the underwriters in connection with this offering:

		Paid by Us
Per Note		%
Total		$

We have also agreed to indemnify the underwriters against certain liabilities, including liabilities under the federal securities laws, or to contribute to payments which the underwriters may be required to make in respect of any such liabilities.

In connection with the offering of the notes, the underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the notes. Specifically, the underwriters may overallot in connection with the offering of the notes, creating a syndicate short position. In addition, the underwriters may bid for, and purchase, notes in the open market to cover syndicate short positions or to stabilize the price of the notes. Finally, the underwriting syndicate may reclaim selling concessions allowed for distributing the notes in the offering of the notes, if the syndicate repurchases previously distributed notes in syndicate covering transactions, stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the notes above independent market levels. The underwriters are not required to engage in any of these activities, and may end any of them at any time.

Expenses associated with this offering to be paid by us, other than the underwriting discount, are estimated to be $ .

The notes offered hereby are further issuance of the existing notes and will become part of the same series as the existing notes. The notes will not be listed on any securities exchange or included in any authorized quotation system.

From time to time in the ordinary course of their respective businesses, certain of the underwriters and their affiliates have engaged in and may in the future engage in commercial banking, derivatives and/or investment banking transactions with us and our affiliates for which they have received, or will receive customary fees and reimbursement of expenses.

In addition, in the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. If any of the underwriters or their affiliates has a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

J.P. Morgan Securities LLC and Citigroup Global Markets Inc. are lead arrangers and book managers of the Omnicom Group credit facility. An affiliate of J.P. Morgan Securities LLC is a syndication agent and an affiliate of Citigroup Global Markets Inc. is an administrative agent of the Omnicom Group credit facility. Certain of the other underwriters are also participants in the Omnicom Group credit facility.

All sales of notes in the United States will be made by or through U.S. registered broker-dealers as permitted by applicable regulations.

Notice to Prospective Investors in the European Economic Area

In relation to each member state of the European Economic Area that has implemented the Prospectus Directive (each, a relevant member state), with effect from and including the date on which the Prospectus Directive is implemented in that relevant member state (the relevant implementation date), an offer of notes described in this prospectus supplement may not be made to the public in that relevant member state other than:

•

to any legal entity which is a qualified investor as defined in the Prospectus Directive;

•

to fewer than 100 or, if the relevant member state has implemented the relevant provision of the 2010 PD Amending Directive, 150, natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the relevant Dealer or Dealers nominated by us for any such offer; or

•

in any other circumstances falling within Article 3(2) of the Prospectus Directive,

provided that no such offer of notes shall require us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Directive.

For purposes of this provision, the expression an “offer of notes to the public” in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe for the notes, as the expression may be varied in that member state by any measure implementing the Prospectus Directive in that member state, and the expression “Prospectus Directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive, to the extent implemented in the relevant member state) and includes any relevant implementing measure in each relevant member state. The expression 2010 PD Amending Directive means Directive 2010/73/EU.

The sellers of the notes have not authorized and do not authorize the making of any offer of notes through any financial intermediary on their behalf, other than offers made by the underwriters with a view to the final placement of the notes as contemplated in this prospectus supplement. Accordingly, no purchaser of the notes, other than the underwriters, is authorized to make any further offer of the notes on behalf of the sellers or the underwriters.

Notice to Prospective Investors in the United Kingdom

Each underwriter has represented and agreed that:

•

it has only communicated or caused to be communicated and will only communicate or cause to be communicated an invitation or inducement to engage in investment activity (within the meaning of Section 21 of the Financial Services and Markets Act 2000 (“FMSA”)) received by it in connection with the issue or sale of the notes in circumstances in which Section 21(1) of the FMSA does not apply to us; and

•

it has complied and will comply with all applicable provisions of the FMSA with respect to anything done by it in relation to the notes in, from or otherwise involving the United Kingdom.

LEGAL MATTERS

Certain legal matters in connection with this offering will be passed upon for the Issuers by Jones Day, New York, New York and/or by its general counsel, Michael O’Brien, Esq. Mr. O’Brien is an officer of Omnicom Group Inc. and has received, and may in the future receive, awards of restricted stock and options and other benefits determined by reference to Omnicom Group Inc. securities. Mr. O’Brien beneficially owns or has rights to acquire a total of less than 1% of Omnicom Group Inc.’s outstanding common stock. In connection with this offering the underwriters have been represented by Shearman & Sterling LLP, New York, New York.

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The consolidated financial statements and financial statement schedule of Omnicom Group Inc. and subsidiaries as of December 31, 2011 and 2010, and for each of the years in the three-year period ended December 31, 2011, and the effectiveness of our internal control over financial reporting as of December 31, 2011, are incorporated by reference herein in reliance upon the reports of KPMG LLP, an independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

This prospectus supplement is a part of a registration statement filed by Omnicom Group Inc., Omnicom Capital, and Omnicom Finance under the Securities Act. The registration statement also includes additional information not contained in this prospectus supplement.

Omnicom Group Inc. files annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document Omnicom Group Inc. files at the SEC’s public reference rooms at 100 F Street N.E., Washington, D.C. 20549. You can also request copies of the documents, upon payment of a duplicating fee, by writing the Public Reference Section of the SEC. Please call the SEC at 1-800-SEC-0330 for further information on the public reference rooms. These SEC filings are also available to the public from the SEC’s web site at http://www.sec.gov.

The SEC allows us to “incorporate by reference” into this prospectus supplement and the accompanying prospectus (as well as the related registration statement) the information we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus supplement as a legal matter. Information that we file later with the SEC will automatically update information in this prospectus supplement. In all cases, you should rely on the later information over different information included in this prospectus supplement or the accompanying prospectus. We incorporate by reference the documents listed below and any future filings made with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934:

•

Annual Report of Omnicom Group Inc. on Form 10-K for the fiscal year ended December 31, 2011 filed with the SEC on February 17, 2012;

•

Quarterly Reports of Omnicom Group Inc. on Form 10-Q for the quarterly periods ended March 31, 2012, filed with the SEC on April 17, 2012, and June 30, 2012, filed with the SEC on July 20, 2012, and as amended by Omnicom Group Inc. on July 20, 2012.

•

Current Reports of Omnicom Group Inc. on Form 8-K filed with the SEC on April 19, 2012, April 23, 2012, May 24, 2012 and July 20, 2012; and

•

Definitive proxy statement of Omnicom Group Inc. on Schedule 14A filed with the SEC on April 12, 2012.

We are not incorporating by reference any information furnished rather than filed under Items 2.02 and 7.01 of any Current Report on Form 8-K.

All documents we file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus supplement and the accompanying prospectus before the later of (1) the completion of the offering of the securities described in this prospectus supplement and (2) if applicable, the date any underwriters stop offering securities pursuant to this prospectus supplement will also be incorporated by reference in this prospectus supplement from the date of filing of such documents. Upon request, we will provide to each person, including any beneficial owner, to whom a prospectus supplement is delivered, a copy of any or all of the information that has been incorporated by reference in this prospectus supplement but not delivered with this prospectus supplement.

This information is also available on the investor relations page of Omnicom Group Inc.’s web site at http://www.omnicomgroup.com. Information included or available through Omnicom Group Inc.’s website does not constitute a part of this prospectus supplement or the accompanying prospectus. You may also request a copy of these filings, at no cost, by writing or telephoning Omnicom Group Inc. at the following address:

Omnicom Group Inc.
437 Madison Avenue
New York, NY 10022
Attn: Corporate Secretary
(212) 415-3600

Pursuant to this prospectus, Omnicom Group Inc., Omnicom Capital Inc. and Omnicom Finance Inc., as co-obligors, may offer from time to time senior or subordinated debt securities (together with guarantees by Omnicom Group Inc. of Omnicom Capital Inc.’s and Omnicom Finance Inc.’s obligations in respect of any such debt securities) and Omnicom Group Inc. may offer from time to time:

• subscription rights to purchase its common stock, preferred stock or warrants; and

• warrants to purchase shares of Omnicom Group Inc. common stock or preferred stock.

Specific terms of these securities will be provided in supplements to this prospectus. The securities may be offered separately or together in any combination and as separate series. You should read this prospectus and any prospectus supplement carefully before you invest.

Omnicom Group Inc.’s common stock is listed on the New York Stock Exchange and trades under the symbol “OMC.”

Investing in these securities involves certain risks. See the information included and incorporated by reference in this prospectus and the accompanying prospectus supplement for a discussion of the factors you should carefully consider before deciding to purchase these securities, including the information under “Risk Factors” in Omnicom Group Inc.’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

We may sell these securities on a continuous or delayed basis directly, through agents, dealers or underwriters as designated from time to time, or through a combination of these methods. We reserve the sole right to accept, and together with any agents, dealers and underwriters, reserve the right to reject, in whole or in part, any proposed purchase of securities. If any agents, dealers or underwriters are involved in the sale of any securities, the applicable prospectus supplement will set forth any applicable commissions or discounts. Our net proceeds from the sale of securities also will be set forth in the applicable prospectus supplement.

You should rely only on the information contained in or incorporated by reference in this prospectus, in any accompanying prospectus supplement or in any free writing prospectus filed by us with the Securities and Exchange Commission, or SEC, and any information about the terms of securities offered conveyed to you by us, our underwriters or our agents. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information contained in or incorporated by reference in this prospectus or any prospectus supplement or in any free writing prospectus is accurate as of any date other than their respective dates.

When used in this prospectus, the term “Omnicom Group” refers to Omnicom Group Inc. together with its consolidated subsidiaries, the term “Omnicom Group Inc.” refers only to Omnicom Group Inc. and not its subsidiaries, the term “Omnicom Capital” refers only to Omnicom Capital Inc., the term “Omnicom Finance” refers only to Omnicom Finance Inc., and the terms, “Issuers,” “we,” “us” and “our” refer collectively to Omnicom Group Inc., Omnicom Capital and Omnicom Finance, in each case, unless otherwise specified.

Omnicom Group is a leading global advertising, marketing and corporate communications company. Omnicom Group’s branded networks and numerous specialty firms provide advertising, strategic media planning and buying, digital and interactive marketing, direct and promotional marketing, public relations and other specialty communications services to over 5,000 clients in more than 100 countries.

Omnicom Group’s agencies, which operate in all major markets around the world, provide a comprehensive range of services in four fundamental disciplines: advertising; customer relationship management, or CRM; public relations; and specialty communications. The services included in these disciplines are:

Omnicom Group Inc. is incorporated in New York and is a holding company. Its principal corporate offices are located at 437 Madison Avenue, New York, NY 10022; One East Weaver Street, Greenwich, CT 06831; and 1800 N. Military Trail, Boca Raton, FL 33431. Its telephone numbers are (212) 415-3600, (203) 618-1500 and (561) 750-5122, respectively.

Omnicom Capital and Omnicom Finance are wholly owned direct subsidiaries of Omnicom Group Inc. Neither Omnicom Capital nor Omnicom Finance has any independent operations or subsidiaries. The sole function of both Omnicom Capital and Omnicom Finance is to provide funding for the operations of Omnicom Group Inc. and its operating subsidiaries by incurring debt and lending the proceeds to the operating subsidiaries. Their respective assets consist of the intercompany loans they make or have made to Omnicom Group Inc.’s operating subsidiaries and the related interest receivables.

Omnicom Capital is incorporated in Connecticut. Its principal office is located at One East Weaver Street, Greenwich, CT 06831 and its telephone number is (203) 625-3000. Omnicom Finance is incorporated in Delaware. Its principal office is located at 437 Madison Avenue, New York, New York 10022 and its telephone number is (212) 415-3600.

This prospectus is part of a registration statement that we filed with the SEC utilizing a “shelf” registration process. Under this shelf process, we may sell any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement will describe: the terms of the securities offered, any initial public offering price, the price paid to us for the securities, the net proceeds to us, the manner of distribution and any underwriting compensation and the other specific material terms related to the offering of the applicable securities. For more detail on the terms of the securities, you should read the exhibits filed with or incorporated by reference in our registration statement of which this prospectus forms a part. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

This prospectus contains summaries of certain provisions contained in some of the documents described herein. Please refer to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of the documents referred to herein have been filed, or will be filed or incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under “Where You Can Find More Information.”

Pursuant to this registration statement Omnicom Group Inc. may offer, issue and sell securities as set forth on the cover page of this prospectus. Because Omnicom Group Inc. is a “well-known seasoned issuer,” as defined in Rule 405 of the Securities Act of 1933, as amended, which we refer to in this prospectus as the “Securities Act,” Omnicom Group Inc. may add to and offer additional securities, including securities held by security holders, by filing a prospectus supplement with the SEC at the time of the offer. In addition, Omnicom Group Inc. is able to add its subsidiaries and securities to be issued by them if Omnicom Group Inc. guarantees such securities. Omnicom Group Inc. will guarantee any debt securities that Omnicom Capital and Omnicom Finance issued under this prospectus.

This prospectus is a part of a registration statement filed by Omnicom Group Inc., Omnicom Capital, and Omnicom Finance under the Securities Act. The registration statement also includes additional information not contained in this prospectus.

Omnicom Group Inc. files annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document Omnicom Group Inc. files at the SEC’s public reference room located at 100 F Street N.E., Washington, D.C. 20549. You can also request copies of the documents, upon payment of a duplicating fee, by writing the Public Reference Section of the SEC. Please call the SEC at 1-800-SEC-0330 for further information on the public reference rooms. These SEC filings are also available to the public from the SEC’s web site at http://www.sec.gov.

The SEC allows us to “incorporate by reference” into this prospectus and any prospectus supplement (as well as the related registration statement) the information we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus as a legal matter. Information that we file later with the SEC will automatically update information in this prospectus. In all cases, you should rely on the later information over different information included in this prospectus or the prospectus supplement. We incorporate by reference the documents listed below and any future filings made with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934:

• Annual Report of Omnicom Group Inc. on Form 10-K for the fiscal year ended December 31, 2011 filed with the SEC on February 17, 2012;

• Definitive proxy statement of Omnicom Group Inc. on Schedule 14A filed with the SEC on April 14, 2011;

• Current reports of Omnicom Group Inc. on Form 8-K filed with the SEC on April 12, 2011, May 26, 2011, July 25, 2011 and October 13, 2011;

• Registration Statement on Form 8-A filed pursuant to Section 12 of the Exchange Act describing Omnicom Group Inc.’s common stock, including any amendments or reports filed for the purpose of updating such description.

All documents we file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this prospectus and before the later of (1) the completion of the offering of the securities described in this prospectus and (2) if applicable, the date any underwriters stop offering securities pursuant to this prospectus will also be incorporated by reference in this prospectus from the date of filing of such documents. Upon request, we will provide to each person, including any beneficial owner, to whom a prospectus is delivered, a copy of any or all of the information that has been incorporated by reference in this prospectus but not delivered with this prospectus.

This information is also available on the investor relations page of Omnicom Group Inc.’s web site at http://www.omnicomgroup.com. Information included or available through Omnicom Group Inc.’s website does not constitute a part of this prospectus or any prospectus supplement. You may also request a copy of these filings, at no cost, by writing or telephoning Omnicom Group Inc. at the following address:

You should rely only on the information provided in this prospectus and any prospectus supplement, as well as the information incorporated by reference. We have not authorized anyone to provide you with different information. You should not assume that the information in this prospectus, the prospectus supplement or any documents incorporated by reference is accurate as of any date other than the date on the front of the applicable document.

Certain of the statements in this prospectus constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. In addition, from time to time, we or our representatives have made or may make forward-looking statements, orally or in writing. These statements relate to future events or future financial performance and involve known and unknown risks and other factors that may cause our actual or our industry’s results, levels of activity or achievement to be materially different from those expressed or implied by any forward-looking statements. These risks and uncertainties, including those resulting from specific factors identified under the captions “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K, include, but are not limited to, our future financial position and results of operations, global economic conditions and conditions in the credit markets, losses on media purchases and production costs incurred on behalf of clients, reductions in client spending and/or a slowdown in client payments, competitive factors, changes in client communication requirements, managing conflicts of interest, the hiring and retention of personnel, maintaining a highly skilled workforce, our ability to attract new clients and retain existing clients, reliance on information technology systems, changes in government regulations impacting our advertising and marketing strategies, risks associated with assumptions we make in connection with our critical accounting estimates and legal proceedings, and our international operations, which are subject to the risks of currency fluctuations and foreign exchange controls. In some cases, forward-looking statements can be identified by terminology such as “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of those terms or other comparable terminology. These statements are our present expectations. Actual events or results may differ. We undertake no obligation to update or revise any forward-looking statement, except as required by law.

Unless otherwise specified in an applicable prospectus supplement, Omnicom Group will use the proceeds it receives from the sale of the offered securities for general corporate purposes, which could include working capital, capital expenditures, acquisitions, refinancing of other debt or other capital transactions. Net proceeds may be temporarily invested prior to use. The precise amounts and timing of the application of proceeds will depend upon the funding requirements of Omnicom Group Inc. and its subsidiaries at the time of issuance and the availability of other funds.

The following table shows the ratio of earnings to fixed charges of Omnicom Group Inc. for each of the five most recent fiscal years.

Since we had no preferred stock outstanding during any of the periods presented, the ratios of earnings to fixed charges and the ratios of earnings to combined fixed charges and preferred dividends are the same.

The following briefly summarizes the material terms of Omnicom Group Inc.’s common stock. You should read the more detailed provisions of Omnicom Group Inc.’s restated certificate of incorporation for provisions that may be important to you.

Omnicom Group Inc.’s restated certificate of incorporation authorizes it to issue up to 1,000,000,000 shares of common stock, par value $.15 per share. As of February 10, 2012, Omnicom Group Inc. had approximately 272,805,000 shares of its common stock outstanding.

Each holder of common stock is entitled to one vote per share for the election of directors and for all other matters to be voted on by Omnicom Group Inc. shareholders. Holders of common stock may not cumulate their votes in the election of directors, and are entitled to share equally in the dividends that may be declared by the board of directors, but only after payment of dividends required to be paid on any outstanding shares of preferred stock.

Omnicom Group Inc.’s shareholders elect the full board of directors annually. An affirmative vote of the holders of a majority of votes cast is required for Omnicom Group Inc.’s shareholders to remove a director, amend Omnicom Group Inc.’s by-laws or its restated certificate of incorporation and to change the number of directors comprising the full board.

The board of directors also has power to amend the by-laws or change the number of directors comprising the full board.

Upon voluntary or involuntary liquidation, dissolution or winding up of Omnicom Group Inc., the holders of the common stock share ratably in the assets remaining after payments to creditors and provision for the preference of any preferred stock. There are currently no preemptive or other subscription rights, conversion rights or redemption or scheduled installment payment provisions relating to shares of common stock. All of the outstanding shares of common stock are fully paid and nonassessable.

The common stock is listed on the New York Stock Exchange under the symbol “OMC.”

The following briefly summarizes the material terms of Omnicom Group Inc.’s preferred stock, other than pricing and related terms to be disclosed in a prospectus supplement. You should read the particular terms of any series of preferred stock offered by Omnicom Group Inc. which will be described in more detail in any prospectus supplement relating to such series, together with the more detailed provisions of Omnicom Group Inc.’s restated certificate of incorporation and the certificate of designation relating to each particular series of preferred stock, for provisions that may be important to you. The restated certificate of incorporation is incorporated by reference as an exhibit to the registration statement of which this prospectus forms a part. The certificate of designation relating to the particular series of preferred stock offered by a prospectus supplement relating to the series’ issue will be filed as an exhibit to one of Omnicom Group Inc.’s future current reports and incorporated by reference in the registration statement to which this prospectus relates. The prospectus supplement will also state whether any of the terms summarized below do not apply to the series of preferred stock being offered.

As of the date of this prospectus, Omnicom Group Inc. is authorized to issue up to 7.5 million shares of preferred stock, par value $1.00 per share, none of which is outstanding.

Under Omnicom Group Inc.’s restated certificate of incorporation, the board of directors of Omnicom Group Inc. is authorized to issue, without the approval of Omnicom Group Inc.’s shareholders, shares of preferred stock in one or more series, and to establish from time to time a series of preferred stock having such powers, preferences, rights and limitations as the board of directors so designates.

Prior to the issuance of any series of preferred stock, the board of directors of Omnicom Group Inc. will adopt resolutions creating and designating the series as a series of preferred stock and the resolutions will be filed with the New York State Secretary of State as an amendment to the restated certificate of incorporation.

The resolutions of the board of directors of Omnicom Group Inc. providing for a series of preferred stock may include the following provisions:

The rights of holders of the preferred stock offered may be affected by the rights of holders of any shares of preferred stock that may be issued in the future. Those effects could be adverse. Shares of preferred stock issued by Omnicom Group Inc. may have the effect of rendering more difficult or discouraging an acquisition of Omnicom Group Inc. deemed undesirable by the board of directors of Omnicom Group Inc.

The preferred stock will be, when issued, fully paid and nonassessable. Holders of preferred stock will not have any preemptive or subscription rights to acquire more stock of Omnicom Group Inc.

The transfer agent, registrar, dividend disbursing agent and redemption agent for shares of each series of preferred stock will be named in the prospectus supplement relating to such series.

Unless otherwise specified in the prospectus supplement relating to the shares of any series of preferred stock, the shares will rank on an equal basis with each other series of preferred stock and prior to the common stock as to dividends and distributions of assets.

Holders of each series of preferred stock will be entitled to receive cash dividends when, as and if declared by the board of directors of Omnicom Group Inc. out of funds legally available for dividends. The rates and dates of payment of dividends will be set forth in the prospectus supplement relating to each series of preferred stock. Dividends will be payable to holders of record of preferred stock as they appear on the books of Omnicom Group Inc. on the record dates fixed by the board of directors. Dividends on any series of preferred stock may be cumulative or noncumulative.

The prospectus supplement for any series of preferred stock will state the terms, if any, on which shares of that series are convertible into or exchangeable for other types of securities of Omnicom Group Inc.

If so specified in the applicable prospectus supplement, a series of preferred stock may be redeemable at any time, in whole or in part, at the option of Omnicom Group Inc. or the holder thereof and may be mandatorily redeemed.

Any partial redemptions of preferred stock will be made in a way that the board of directors decides is equitable.

Unless Omnicom Group Inc. defaults in the payment of the redemption price, dividends will cease to accrue after the redemption date on shares of preferred stock called for redemption and all rights of holders of such shares will terminate except for the right to receive the redemption price.

Upon any voluntary or involuntary liquidation, dissolution or winding up of Omnicom Group Inc., holders of each series of preferred stock will be entitled to receive distributions upon liquidation in the amount set forth in the prospectus supplement relating to such series of preferred stock, plus an amount equal to any accrued and unpaid dividends. Those distributions will be made before any distribution is made on any securities ranking junior relating to liquidation, including common stock.

If the liquidation amounts payable relating to the preferred stock of any series and any other securities ranking on a parity regarding liquidation rights are not paid in full, the holders of the preferred stock of such series and such other securities will share in any such distribution of available assets of Omnicom Group Inc. on a ratable basis in proportion to the full liquidation preferences.

Holders of preferred stock will not be entitled to any other amounts from Omnicom Group Inc. after they have received their full liquidation preference.

The description below of the general terms of the debt securities will be supplemented by the more specific terms of a particular series in a prospectus supplement.

The debt securities offered by this prospectus will be joint and several unsecured obligations of Omnicom Group Inc., Omnicom Capital and/or Omnicom Finance and will be either senior or subordinated debt. We will issue the debt securities under an indenture between us and Deutsche Bank Trust Company Americas, or the Trustee. The indenture provides that our debt securities may be issued in one or more series, with different terms, in each case as authorized from time to time by us. The indenture also gives us the ability to reopen a previous issue of a series of debt securities and issue additional debt securities of that series or establish additional terms for that series of debt securities. The indenture does not limit the amount of debt securities or other unsecured debt which we may issue.

Neither the senior debt securities nor the subordinated debt securities will be secured by any of our property or assets. Thus, by owning a debt security, you are one of our unsecured creditors.

In addition to the following description of the debt securities, you should refer to the detailed provisions of the indenture.

If material, federal income tax consequences and other special considerations applicable to any debt securities issued by the Issuers at a discount will be described in the applicable prospectus supplement.

The debt securities will represent direct, unsecured, general obligations of the Issuers and:

Omnicom Group Inc. is a holding company and Omnicom Capital and Omnicom Finance are finance subsidiaries. As finance subsidiaries, Omnicom Capital’s and Omnicom Financial’s respective assets consist of the intercompany loans they make or have made to Omnicom Group Inc.’s operating subsidiaries and the related interest receivables. As a result, the debt securities issued under the indenture will effectively be subordinated to all existing and future obligations of Omnicom Group Inc.’s operating subsidiaries, including trade payables, and to the Issuers’ respective obligations that are secured, to the extent of the security. Omnicom Capital’s and Omnicom Finance’s obligations in respect of any debt securities will be guaranteed by Omnicom Group Inc.

The aggregate principal amount of debt securities that the Issuers may authenticate and deliver is unlimited. You should refer to the applicable prospectus supplement for the following terms of the debt securities of the series with respect to which that prospectus supplement is being delivered:

The terms on which a series of debt securities may be convertible into or exchangeable for common stock or preferred stock of Omnicom Group Inc. will be set forth in the prospectus supplement relating to such series. Such terms will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at the option of the Issuers. The terms may include provisions pursuant to which the number of shares of common stock or other securities of Omnicom Group Inc. to be received by the holders of such series of debt securities may be adjusted.

The debt securities will be issued only in registered form. Debt securities of a series will either be global securities registered in book-entry form, or a physical (paper) certificate issued in definitive, or certificated, registered form. Procedures relating to global securities are described below under “Book-Entry Procedures and Settlement.” Unless otherwise provided in the applicable prospectus supplement, debt securities denominated in United States dollars will be issued only in denominations of $1,000 and whole multiples of $1,000. The prospectus supplement relating to offered securities denominated in a foreign or composite currency will specify the denomination of the offered securities.

Debt securities represented by a paper certificate may be presented for exchange or transfer at the office of the Registrar. Holders will not have to pay any service charge for any registration of transfer or exchange of their

certificates, but the Issuers may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with such registration of transfer.

Distributions on the debt securities other than those represented by global notes will be made in the designated currency against surrender of the debt securities at the principal office of the paying agent. Payment will be made to the registered holder at the close of business on the record date for such payment. Interest payments will be made at the principal corporate trust office of the trustee in New York City, or by a check mailed to the holder at his registered address. Payments in any other manner will be specified in the prospectus supplement.

The debt securities will be issued in book-entry form only and represented by one or more global securities registered in the name of, and deposited with a custodian for, The Depository Trust Company, or DTC, or its nominee. DTC or its nominee will be the sole registered holder of the debt securities for all purposes under the indenture. Owners of beneficial interests in the debt securities represented by the global securities will hold their interests pursuant to the procedures and practices of DTC. As a result, beneficial interests in these securities will be shown on, and may only be transferred through, records maintained by DTC and its direct and indirect participants and any such interest may not be exchanged for certificated securities, except in limited circumstances. Owners of beneficial interests must exercise any rights in respect of their interests, in accordance with the procedures and practices of DTC. Beneficial owners will not be holders and will not be entitled to any rights provided to the holders of debt securities under the global securities or the indenture. The Issuers and the trustee, and any of their respective agents, may treat DTC as the sole holder and registered owner of the global securities under the terms of the indenture.

Unless an applicable prospectus supplement specifies otherwise, the debt securities will not be redeemable. In the event the debt securities are redeemable, the debt securities will be redeemable, as a whole or in part, at the Issuers’ option, at any time or from time to time, upon mailed notice to the registered address of each holder of debt securities at least 30 days but not more than 60 days prior to the redemption. The redemption price will be equal to the greater of (1) 100% of the principal amount of the debt securities to be redeemed and (2) the sum of the present values of the Remaining Scheduled Payments (as defined below) on such debt securities discounted to the date of redemption, on a semiannual basis (assuming a 360-day year consisting of twelve 30-day months), at a rate equal to the sum of the applicable Treasury Rate (as defined below) plus a make whole spread, which will be specified in the applicable prospectus supplement, plus accrued and unpaid interest thereon to the redemption date.

“Treasury Rate” means, with respect to any redemption date, the rate per annum equal to the semiannual equivalent yield to maturity (computed as of the third business day immediately preceding that redemption date) of the Comparable Treasury Issue (as defined below), assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for that redemption date.

“Comparable Treasury Issue” means the United States Treasury security selected by the Reference Treasury Dealer (as defined below) as having a maturity comparable to the remaining term of the debt securities, that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of the debt securities.

“Comparable Treasury Price” means, with respect to any redemption date, the Reference Treasury Dealer Quotations (as defined below) for that redemption date.

“Reference Treasury Dealer” means each of any three primary U.S. Government securities dealer selected by us, and their respective successors.

“Reference Treasury Dealer Quotations” means, with respect to the Reference Treasury Dealer and any redemption date, the average, as determined by the trustee, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the trustee by the Reference Treasury Dealer at 3:30 p.m., New York City time, on the third business day preceding that redemption date.

“Remaining Scheduled Payments” means the remaining scheduled payments of principal of and interest on the debt securities that would be due after the related redemption date but for that redemption. If that redemption date is not an interest payment date with respect to the debt securities, the amount of the next succeeding scheduled interest payment on the debt securities will be reduced by the amount of interest accrued on the debt securities to such redemption date. On and after the redemption date, interest will cease to accrue on the debt securities or any portion of the debt securities called for redemption (unless we default in the payment of the redemption price and accrued interest). On or before the redemption date, we will deposit with a paying agent (or the trustee) money sufficient to pay the redemption price of and accrued interest on the debt securities to be redeemed on that date. If less than all of the debt securities are to be redeemed, the debt securities to be redeemed shall be selected by the trustee by a method the trustee deems to be fair and appropriate.

The Issuers may not consolidate with or merge into, or convey, transfer or lease their respective properties and assets as an entirety or substantially as an entirety to, any person, referred to as a “successor person,” except in the case of Omnicom Capital and Omnicom Finance with, into or to Omnicom Group Inc., each other or any other subsidiary of Omnicom Group Inc., unless:

Under the indenture, the Issuers and the trustee may enter into supplemental indentures without obtaining the consent of any holder of debt securities:

The Issuers and the trustee may, with the consent of the holders of at least a majority in aggregate principal amount of the debt securities of a series, modify the indenture or the rights of the holders of the securities of the series to be affected. No modifications may, without the consent of the holder of each security affected, be made that, as to any non-consenting holders:

The indenture provides that events of default regarding any series of debt securities will be:

If an event of default (other than the bankruptcy provision) regarding debt securities of any series issued under the indenture should occur and be continuing, either the trustee or the holders of 25% in the principal amount of outstanding debt securities of such series may declare each debt security of that series due and payable. If a bankruptcy event occurs, the principal of and accrued and unpaid interest on the debt securities of such series shall immediately become due and payable without any declaration or other act on the part of the trustee or the holders of the debt securities of such series. The holders of a majority in principal amount of debt securities of such series may rescind any other declaration or acceleration and its consequences if the rescission would not conflict with any judgment or decree and if all existing events of default have been cured or waived (other than nonpayment of principal or interest that has become due solely as a result of acceleration). The Issuers are required to file annually with the trustee a statement of an officer as to the fulfillment by the Issuers of their respective obligations under the applicable indenture during the preceding year.

Holders of a majority in principal amount of the outstanding debt securities of any series will be entitled to control certain actions of the trustee under the applicable indenture. Holders of a majority in principal amount of the outstanding debt securities of any series also will be entitled to waive past defaults regarding the series, except for a default in payment of principal, premium or interest or a default in a covenant or provision which may not be modified or amended without the consent of each holder of a debt security of the affected series. The trustee generally may not be ordered or directed by any of the holders of debt securities to take any action, unless one or more of the holders shall have offered to the trustee reasonable security or indemnity.

If an event of default occurs and is continuing regarding a series of debt securities, the trustee may use any sums that it holds under the applicable indenture for its own reasonable compensation and expenses incurred prior to paying the holders of debt securities of such series.

Before any holder of any series of debt securities may institute action for any remedy, except payment on the holder’s debt security when due, the holders of not less than 25% in principal amount of the debt securities of that series outstanding must request the trustee to take action. Holders must also offer and give the satisfactory security and indemnity against liabilities incurred by the trustee for taking such action.

The indenture provides that the Issuers may specify with respect to any series of debt securities that after the Issuers have deposited with the trustee, cash or government securities, in trust for the benefit of the holders sufficient to pay the principal of, premium, if any, and interest on and any mandatory sinking fund payments in respect of the debt securities of such series when due, then the Issuers:

In each case, the Issuers must also deliver to the trustee an opinion of counsel to the effect that the holders of the debt securities of such series will have no federal income tax consequences as a result of such deposit.

In addition, the indenture provides that if we choose to have the defeasance and discharge provision applied to the subordinated debt securities, the subordination provisions of the indenture will become ineffective upon full defeasance of the subordinated debt securities.

When there is a defeasance and discharge, (1) the indenture will no longer govern the debt securities of such series, (2) the Issuers will no longer be liable for payment, and (3) the holders of the debt securities will be entitled only to the deposited funds. When there is a covenant defeasance, however, the Issuers will continue to be obligated to make payments when due if the deposited funds are not sufficient.

Debt securities of a series, and any guarantees, may be subordinated, which we refer to as subordinated debt securities, to senior indebtedness (as defined in the applicable prospectus supplement) to the extent set forth in the

prospectus supplement relating thereto. To the extent we conduct operations through subsidiaries, the holders of debt securities (whether or not subordinated debt securities) will be structurally subordinated to the creditors of our subsidiaries except to the extent such subsidiary is a guarantor of such series of debt securities.

The Issuers may from time to time, without notice to or the consent of the registered holders of a series of debt securities, create and issue further debt securities of any such series ranking equally with the debt securities of the corresponding series in all respects (or in all respects other than the payment of interest accruing prior to the issue date of such further debt securities or except for the first payment of interest following the issue date of such further debt securities). Such further debt securities may be consolidated and form a single series with the debt securities of the corresponding series and have the same terms as to status, redemption or otherwise as the debt securities of the corresponding series.

The trustee may engage in transactions with, or perform services for, the Issuers and affiliates of the Issuers in the ordinary course of business. The trustee will perform only those duties that are specifically set forth in the indenture unless an event of default under the indenture occurs and is continuing. In case an event of default occurs and is continuing, the trustee will exercise the same degree of care and skill as a prudent individual would exercise in the conduct of his or her own affairs.

The debt securities and the indenture will be governed by, and construed in accordance, with the laws of the State of New York.

The following briefly summarizes the material terms and provisions of the subscription rights that Omnicom Group Inc. may offer pursuant to this prospectus, other than pricing and related terms which will be disclosed in a prospectus supplement. You should read the particular terms of the subscription rights that are offered by Omnicom Group Inc., which will be described in more detail in a prospectus supplement. The prospectus supplement will also state whether any of the general provisions summarized below do not apply to the subscription rights being offered.

Omnicom Group Inc. may issue subscription rights to purchase common stock, preferred stock, or warrants to purchase preferred stock or common stock. Subscription rights may be issued independently or together with any other offered security and may or may not be transferable by the person purchasing or receiving the subscription rights. In connection with any subscription rights offering to our stockholders, we may enter into a standby underwriting arrangement with one or more underwriters pursuant to which such underwriters will purchase any offered securities remaining unsubscribed for after such subscription rights offering. In connection with a subscription rights offering to our stockholders, we will distribute certificates evidencing the subscription rights and a prospectus supplement to our stockholders on the record date that we set for receiving subscription rights in such subscription rights offering.

The applicable prospectus supplement will describe the following terms of subscription rights in respect of which this prospectus is being delivered:

Each subscription right will entitle the holder of the subscription right to purchase for cash such amount of shares of preferred stock, common stock, warrants or any combination thereof, at such exercise price as shall in each case be set forth in, or be determinable as set forth in, the prospectus supplement relating to the subscription rights offered thereby. Subscription rights may be exercised at any time up to the close of business on the expiration date for such subscription rights set forth in the prospectus supplement. After the close of business on the expiration date, all unexercised subscription rights will become void.

Subscription rights may be exercised as set forth in the prospectus supplement relating to the subscription rights offered thereby. Upon receipt of payment and the subscription rights certificate properly completed and duly executed at the corporate trust office of the subscription rights agent or any other office indicated in the prospectus supplement, we will forward, as soon as practicable, the shares of preferred stock or common stock, depositary shares or warrants purchasable upon such exercise. We may determine to offer any unsubscribed offered securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby underwriting arrangements, as set forth in the applicable prospectus supplement.

The following briefly summarizes the material terms and provisions of the warrants to purchase common stock or preferred stock that Omnicom Group Inc. may offer pursuant to this prospectus, other than pricing and related terms which will be disclosed in a prospectus supplement. You should read the particular terms of the warrants that are offered by Omnicom Group Inc., which will be described in more detail in a prospectus supplement. The prospectus supplement will also state whether any of the general provisions summarized below do not apply to the warrants being offered. A copy of each form of warrant agreement, including the form of certificate that will represent a particular warrant, will be filed as an exhibit to one of Omnicom Group Inc.’s future SEC reports and incorporated by reference in the registration statement to which this prospectus relates. You should read the more detailed provisions of the specific warrant agreement and the warrant certificate for provisions that may be important to you.

Warrants may be issued independently or together with common stock, preferred stock or debt securities, as applicable, and will be separate from any such offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between Omnicom Group Inc. and a bank or trust company, as warrant agent. A single bank or trust company may act as warrant agent for more than one series of warrants. The warrant agent will act solely as the agent of Omnicom Group Inc. under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust for or with any owners of such warrants.

The applicable prospectus supplement will describe the terms of common stock warrants or preferred stock warrants offered, the stock warrant agreement relating to the common stock warrants or preferred stock warrants, and the common stock warrant certificates or the preferred stock warrant certificates representing the common stock warrants or preferred stock warrants, as applicable, including the following:

Each warrant entitles the holder to purchase for cash the principal amount of debt securities or shares of common stock or preferred stock at the exercise price set forth in the prospectus supplement relating to the offered warrants.

The prospectus supplement for the offered warrants will describe the procedures for exercising the warrants and will set forth the expiration date of the warrants. Upon exercise of the warrants, Omnicom Group Inc. will forward the shares of common stock or preferred stock purchased. If less than all of the warrants represented by the warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants. Warrants may be exercised at any time up to the close of business on the expiration date set forth in the prospectus supplement for the offered warrants. After the close of business on the expiration date, unexercised warrants will become void.

We may sell the offered securities (a) through agents; (b) through underwriters or dealers; (c) directly to one or more purchasers; or (d) through a combination of any of these methods of sale. We will identify the specific plan of distribution, including any underwriters, dealers, agents or direct purchasers and their compensation in a prospectus supplement.

In connection with particular offerings of the securities in the future, and if stated in the applicable prospectus supplements, the validity of those securities may be passed upon for us by Jones Day, New York, New York and for any underwriters or agents by counsel named in the applicable prospectus supplement. Certain legal matters in connection with the securities and any offering of those securities will be passed upon for us by our general counsel, Michael O’Brien, Esq. Mr. O’Brien is an officer of Omnicom Group Inc. and has received, and may in the future receive, awards of restricted stock and other benefits determined by reference to Omnicom Group Inc. securities. Mr. O’Brien beneficially owns or has rights to acquire a total of less than 1% of Omnicom Group Inc.’s outstanding common stock.

The consolidated financial statements and financial statement schedule of Omnicom Group Inc. and subsidiaries as of December 31, 2011 and 2010, and for each of the years in the three-year period ended December 31, 2011, and the effectiveness of our internal control over financial reporting as of December 31, 2011, are incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.