Elite Manhattan firms Simpson Thacher & Bartlett and Skadden Arps Slate Meagher & Flom have taken lead roles on Mars’ merger with rival confectionary group Wm Wrigley Jr Co – one of the largest M&A deals of the year so far.

The deal – worth approximately $23bn (£11.5bn) – sees Simpson Thacher client Mars acquire Wrigley, with Warren Buffet’s Berkshire Hathaway investment group taking a $2.1bn (£1.05bn) stake in Wrigley.