Washington ? The Federal Reserve pushed short-term interest rates higher Wednesday, part of a campaign begun last June and expected to continue well into this year to keep inflation and the economy on an even keel.

Fed Chairman Alan Greenspan and his colleagues raised the target for the federal funds rate by one-quarter of a percentage point, to 2.50 percent. It was the sixth such increase since last summer. The rate is the interest that banks charge each other and is the Fed’s main lever for influencing economic activity.

Workers in the Credit Suisse First Boston booth watch monitors on the floor of the New York Stock Exchange as the decision of the Federal Reserve Board to raise interest rates is announced. The increase in short-term interest rates on Wednesday is the sixth boost since June as policy-makers continue their efforts to make sure a strengthening economy does not trigger unwanted inflation.

In a brief statement released after the Fed’s two-day meeting, policy-makers stuck to their gradual ap-proach of raising interest rates. Further increases can be “at a pace that is likely to be measured,” according to the statement, similar to one issued at the previous meeting in December.

Economists said there was nothing in the statement to suggest that policy-makers will either speed up or slow down their rate-raising campaign.

“All the stars seem to be aligned to support a gradualist approach,” said Anthony Chan, senior economist at JPMorgan Fleming Asset Management.

The Fed said the economy was growing “at a moderate pace despite the rise in energy prices, and labor market conditions continue to improve gradually.” Inflation, the Fed said, remains “well contained.”

On Wall Street, the Fed’s action helped boost stocks.