TOKYO, May 20 (Reuters) - Fast food operator KFC Holdings Japan said on Monday that a Carlyle Group-backed fund launched a tender offer for its shares.

Crispy Holdings will offer 6,500 yen per share, a 20% premium to KFC Holding's closing price on Monday. The tender period will last from May 21 to July 9.

Mitsubishi Corp., the biggest shareholder in KFC Holdings with a 35% stake, said separately it would tender all its shares to the offer. The fried chicken chain will become a wholly owned subsidiary after the deal closes, Mitsubishi said.

(Reporting by Kantaro Komiya and Rocky Swift; Editing by Kim Coghill)