OSLO, Sept 13 (Reuters) - U.S. investment firm Kohlberg Kravis Roberts (KKR) has offered to buy Norwegian ship owning company Ocean Yield for 7.2 billion Norwegian crowns ($829 million), the two companies said in a joint statement on Monday.

Ocean Yield's board supported the bid, and its top owner, Norway's Aker ASA, said it had agreed to sell its 61.65% stake to KKR. ($1 = 8.6872 Norwegian crowns) (Reporting by Terje Solsvik; Editing by Kim Coghill)