Faced with slumping sales in its biggest markets, McDonald's has announced the first steps of a global turnaround strategy, acknowledging that a business that has served up billions of burgers on the cheap was in urgent need of change.

Investors and franchisees had been closely watching Steve Easterbrook, McDonald's new chief executive, for details on how he intends to reverse years of lacklustre growth at one of the world's largest restaurant chains, perhaps with a revamped menu.