Omnicom Group, one of the world’s largest advertising agencies, said on Monday December 9 2024 that it had agreed to acquire Interpublic Group, a large rival. If successful, the all-stock takeover would create the biggest ad agency in the world, with more than 100,000 employees and some $25 billion in annual revenue. Under the deal, which Omnicom said it expected to close in the second half of 2025, Omnicom shareholders would own about 60 percent of the combined company, with Interpublic shareholders holding the rest. The combined company would keep the Omnicom name. Omnicom was created in 1986 as part of a three-way merger of ad agencies including BBDO Worldwide. It owns the agencies TBWA, OMD and the digital commerce company Flywheel.