WASHINGTON, Feb 23 (Reuters) - U.S. bank profits fell 36.5% in 2020 from the year prior as banks set aside massive amounts to guard against potential losses, but the industry showed signs of strengthening in the fourth quarter as the economy begins to recover from the pandemic, a regulator reported Tuesday. The industry posted $147.9 billion in profits in 2020, a sharp decline from record 2019 profits, according the Federal Deposit Insurance Corporation, However, bank profits were up 9.1% in the fourth quarter to $59.9 billion compared to a year prior as firms shrank how much cash they set aside to guard against losses. (Reporting by Pete Schroeder)