WASHINGTON (Reuters) - U.S. bank regulators on Friday closed MagnetBank, a small Utah bank, bringing the total of bank failures this year to four. The Federal Deposit Insurance Corp said it could not find a buyer for MagnetBank's banking operations, but that it had approved the payout of the bank's insured deposits. FDIC was named as the receiver of the bank, which had total assets of $292.9 million and total deposits of $282.8 million.