Bank of America Corp. and Citigroup Inc. are among lenders that may find it more difficult to boost profits and capital after the Federal Reserve pledged to keep its benchmark interest rate low until at least late 2014.

“This hurts the banks, I don't think there's any question about that,” said Ralph Cole, a senior vice president of research at Ferguson Wellman Inc. in Portland, Oregon, which manages $2.9 billion. “Their cost of funds stays low but it makes it harder to earn a return.”

The Federal Open Market Committee said yesterday that economic conditions are likely to warrant “exceptionally low levels for the federal funds rate at least through late 2014.” The policy may hurt lenders' profits as they struggle to find loans or securities with yields high enough to support their net interest margins, a gauge of profitability that measures the difference between the cost of funds and what they earn on assets.