US company Omnicom and French firm Publicis say they are combining in a "merger of equals" that will create the world's largest advertising firm with a value of more than $30 billion (£20bn).
The combined company will be called Publicis Omnicom Group and be jointly led by Omnicom CEO John Wren and Publicis CEO Maurice Levy as co-chief executives.
More top news
At least two people have died and more than 120 others have been injured after an earthquake rocked Turkey and the Greek island of Kos.
The son Cecil the lion, whose 2015 killing prompted an international outcry, has also been fatally shot during a hunt.
Thickening cloud and rain stalling across Wales and southwest England through tomorrow