The Seminole Tribe of Florida said yesterday that it had acquired Hard Rock International, the music-themed chain of restaurants, hotels and casinos, from the Rank Group of Britain for $965 million, one of the largest purchases ever by an American Indian tribe.

The sale signals the exit of Rank from the restaurant industry, as it seeks to focus on its casino operations amid disappointing earnings. It is also the Seminoles’ largest acquisition yet in gambling, a business the tribe first entered in 1979 with a series of bingo halls. The tribe, which currently draws about 90 percent of its income from gambling, has sought in recent years to diversify its revenue streams.

“You’re here for a special day in Seminole history,” said Max B. Osceola Jr., a Seminole council representative. “Our ancestors sold Manhattan for trinkets. We’re going to buy Manhattan back, one burger at a time.”

Rank put Hard Rock up for sale this summer. In trading in London yesterday, shares of Rank fell more than 4 percent, to 255.5 pence amid concerns that it had sold the franchise for too low a price.