DETROIT — Fiat Chrysler CEO Mike Manley will run operations in the Americas when his company merges with France’s PSA Peugeot early next year.

FCA Chairman John Elkann announced Manley’s new post Friday in a letter to employees. Manley’s role in the merged company had been a mystery.

PSA CEO Carlos Tavares will run the overall company, to be named Stellantis.

Shareholders of both companies will vote on the merger Jan. 4 to seal the deal creating the world’s fourth-largest automaker. The merger is expected to be completed by the end of March.

The Americas, especially the U.S., are key to the new company’s success.