A mixed picture of U.S. banks emerged Tuesday as the industry posted its highest quarterly earnings in nearly three years while the number of troubled institutions grew by more than 50.

Banks overall made $21.6 billion in net income in the April-to-June quarter, the Federal Deposit Insurance Corp. said. It was the highest quarterly level since 2007 and was led by the largest institutions. The industry lost $4.4 billion in the second quarter of 2009.

But the number of banks on the FDIC's confidential "problem" list increased by 54 in the quarter -- growing to 829 from 775 in the first quarter. Most of the banks that have failed this year have been smaller or regional banks.

The decline in bank lending stemming from the financial crisis showed signs of leveling off, the data show. Total lending declined by $107.5 billion, or 1.4 percent from the first quarter. It posted the steepest drop since World War II -- 7.5 percent -- in 2009 from the year before.