WASHINGTON – The Federal Reserve said Wednesday that it plans to keep interest rates ultra-low even after unemployment falls close to a normal level — which could take three years.

If expected inflation remains tame, the Fed could keep its key short-term rate near zero even after unemployment falls below 6.5 percent (it is now 7.7 percent).

For the first time, the Fed is making clear to investors and consumers that it will link its actions to specific economic markers. Previously the Fed had said only that it expects to keep the rate low until at least mid-2015.

Analysts said the Fed’s new guidance will make it easier for companies, investors and consumers to make financial decisions because they will have a clearer grasp of when borrowing costs will begin to rise.