(Adds details from the release, compares with estimates, background)

Oct 15 (Reuters) - U.S. advertising company Omnicom Group Inc fell short of Wall Street estimates for quarterly revenue on Tuesday, hurt by a stronger dollar.

The company also reported a 2.2% increase in revenue from organic growth - a widely watched measure that excludes fluctuation in foreign exchange rates and mergers. Analysts on average had expected a 2.75% gain, according to four analysts polled by Refinitiv IBES.

Counted among the world's "Big Four" traditional ad companies, Omnicom and other traditional advertisers face competition from internet giants like Alphabet Inc's Google and Facebook Inc as well as consulting firms such as Accenture Plc, IBM Corp.

Last week, French advertising firm Publicis Groupe SA cut its full-year sales target for the second time.

Net income attributable to the company fell to $290.2 million, or $1.32 per share, in the quarter ended Sept. 30, from $298.9 million, or $1.32 per share, a year earlier.

Analysts were expecting a profit of $1.31 per share, according to IBES data from Refinitiv.

The company, which counts McDonald's, Johnson & Johnson and Volkswagen as clients, said revenue fell 2.4% to $3.62 billion. Analysts were expecting revenue of $3.65 billion.

(Reporting by Ambhini Aishwarya in Bengaluru; Editing by Aditya Soni)