NEW YORK — McDonald’s Corp., the world’s biggest hamburger chain, said Jan Fields, president of McDonald’s USA, will be replaced by Jeff Stratton, its global chief restaurant officer, Dec. 1. The news came less than a week after the chain posted its first monthly sales drop in nearly a decade.

A McDonald’s spokeswoman denied that sales figures were among the reasons for the change.

After years of outperforming its rivals, McDonald’s has struggled recently amid intensifying competition at home and a weak economy abroad.

The United States accounts for a third of McDonald’s revenue. Europe accounts for 40 percent; the region encompassing Asia, the Middle East and Africa 22 percent.

Fields, 57, was named president in 2010 and started with the company as a crew member more than 35 years ago.

Stratton oversees operations and innovation. He started as a crew member more than 40 years ago.