Omnicom and IPG sent shockwaves through the advertising sector when they announced a $13bn merger on Monday. Ali Lyon looks at what the deal means for the firms’ agencies, staff and the ad industry as a whole.

The $13.25 billion acquisition by the ad holding company Omnicom of Interpublic Group has industry insiders speculating about more M&A to come.

Omnicom and IPG expect to make $750m (£587m) in “annual cost synergies”, and there was no immediate word on where the cuts may fall. The combined company is expected to have a stock market capitalisation of more than $30bn (£23bn).The deal is expected to close in the second half of 2025, the companies said.