In a surprise move taken between its regular meetings, the Federal Reserve Board cut interest rates Wednesday – the fourth time it has done so this year.

The Fed said in a statement that its policy makers cut the target for the federal funds rate, an overnight bank lending rate, by half a percentage point to 4.5%. It also lowered the rarely used discount rate, for loans by the Fed to banks, a half point to 4%.

The action came as most U.S. corporations are releasing first-quarter earnings statements to its shareholders. Caterpillar Inc., J. B. Hunt Transport Services Inc. and Wabash National Corp. were among companies reporting lower earnings this week.

The board said the severe slowdown in capital spending by big corporations “threatens to keep the pace of economic activity unacceptably weak. As a consequence, the policy makers committee agreed that an adjustment in rates was needed.”

The Fed's next regular meeting is scheduled for May.