Copies of scripture are being left in the rooms of hotels which have merged with Marriott in recent years, including those belonging to the Sheraton, Westin and Starwood chains.
The extra Bibles should be available to guests by the end of the year. It is understood many other mainstream hotel chains allow managers discretion in deciding whether rooms are stocked with a Bible.
Marriott International stipulates in its franchise and licencing agreements that a copy of the Bible and the Book of Mormon must be left in every room.
Company bosses told Associated Press: "There are many guests who are not digitally connected who appreciate having one or both of these books available.
"It's a tradition appreciated by many, objected to by few."
Some smaller, subsidiary brands are not expected to comply with the agreement. And Marriott hotels operating in countries were other religious are popular - such as Muslim-majority Indonesia - are also exempt.
Founded by a family which has been active within the Mormon Church, Marriott International has placed Bibles and the Book of Mormon in rooms since its first hotel was established in Virginia in 1957.
Bibles in Marriott International hotel rooms are provided by Gideons International, a US-headquartered organisation which placed copies of scripture in public places like prisons and hospital.
Marriott International boasts more than 6,500 properties across 127 countries and territories.
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