Mariott Hotels.

Marriott International Inc. says the policy change, which it called the largest in its industry, covers more than 2,300 hotels and corporate apartments with nearly 400,000 rooms will make all of its hotels in the United States and Canada entirely non-smoking, beginning in September.

The change covers such brands as Marriott, Ritz-Carlton, Renaissance, Courtyard, Residence Inn and Fairfield Inn. Marriott has nearly 2,800 lodging properties in the United States and 67 other countries.

Marriott, based in Bethesda, Maryland, said more than 90 percent of its guest rooms are already non-smoking. It said more customers have been demanding non-smoking rooms.