The Omnicom and Interpublic merger was agreed at the end of 2024 in a stock-for-stock transaction.

The agreement would see Omnicom shareholders own 60.6% of the combined company and Interpublic shareholders own 39.4%, on a fully diluted basis.

The CMA had launched a merger inquiry into the proposed deal in June, after opening an invitation for comment on the deal the prior month. The full text of the decision to agree to the merger will be released in due course.

In July, the proposed merger cleared a similar investigation by the Australian Competition and Consumer Commission, and the deal is expected to close in the second half of this year.

Omnicom and IPG expect the transaction to generate ‘annual cost synergies’ of $750m.

Omnicom is the owner of networks Omnicom Media Group (OMG), Flywheel and the DAS Group of Companies. Businesses include advertising group DDB, data and analytics division Annalect, branding agency Interbrand and media agency Hearts and Science.

Interpublic’s agencies include media network UM, advertising agencies FCB and McCann and media and marketing services arm IPG Mediabrands.

Both are headquartered in New York. Omnicom employs around 75,000 people globally, while IPG has a headcount of 55,000.