Hotel operator Starwood Hotels & Resorts Worldwide Inc. named Thomas B. Mangas as CEO to replace the departing Adam Aron, who is taking the reins of the theater chain AMC Entertainment Holdings Inc.

The moves come as hotel behemoth Marriott International is in the process of buying Starwood in a $12.2 billion deal, which is expected to close in the middle of 2016.

Mangas is currently executive vice president and chief financial officer at Starwood.

Starwood has more than 1,270 properties in some 100 countries worldwide, including brands such as St. Regis, W, Westin and Sheraton.

On Monday, AMC Entertainment said Aron would replace interim CEO Craig Ramsey. Ramsey will remain chief financial officer and report to Aron.

Aron, 61, headed Starwood as interim boss since February. He is also the former CEO of the Philadelphia 76ers and has been chief executive of Vail Resorts Inc. and Norwegian Cruise Line Ltd.

AMC, the nation’s second largest movie theater chain, has been publicly traded since December 2013. It is controlled by Chinese theater giant Dalian Wanda Group Co. Ltd., which bought it in September 2012 in a $2.6 billion deal.