Feb 7 (Reuters) - Omnicom Group Inc, the No. 1 U.S. advertising company, reported a 2.1 percent rise in quarterly revenue due to heavy spending on ads by businesses in the United States.
The company's net income rose to $348.7 million, or $1.47 per share, in the fourth quarter ended Dec. 31, from $328.3 million, or $1.35 per share, a year earlier.
Revenue rose to $4.24 billion from $4.15 billion.
Subsidiaries of Omnicom and fellow competitor Publicis Groupe SA were subpoenaed by the U.S. Department of Justice in December, as part of an investigation whether ad agencies had rigged bids to favor in-house production units.
Rival Interpublic Group of Cos Inc earlier in December said that one of its domestic agencies had been contacted by the DoJ as part of the investigation. (Reporting by Aishwarya Venugopal in Bengaluru; Editing by Shounak Dasgupta)