Bank of America on Monday reported a drop in second-quarter earnings as the drag of low interest rates offset a pickup in some key consumer banking categories.

Chief executive officer Brian Moynihan said the earnings, which topped expectations, nevertheless reflected the bank's engineering of "another solid quarter in a challenging environment" by keeping a lid on expenses.

Net income for the quarter ending June 30 was $3.9 billion, down 19.4 percent.

Revenue fell 7.1 percent to $20.4 billion.

BofA, the third-largest US bank by assets, reported a hefty drop in net interest income as global central banks keep interest rates low. On the positive side, total loans grew 2.5 percent to $903.2 billion.

The bank's income for consumer banking rose as it notched its highest level of US consumer credit cards since 2008.

BofA said the credit hit from poor energy prices had stabilized and that its exposure to bad energy loans had declined compared with the prior quarter.