Banks borrowed less from the Federal Reserve's emergency lending program over the past week as it becomes easier to borrow in the private credit markets.

Commercial banks averaged $15.1 billion in daily borrowing for the week that ended Wednesday, the Fed reported Thursday. That was down from $17.5 billion in average borrowing for the previous week.

Banks have scaled back their use of the Fed's emergency discount loan window as credit markets have thawed in the past year. At the peak of the crisis, which struck in the fall of 2008, banks' daily borrowing from the discount window reached $110 billion as lenders panicked and credit markets locked up.

Banks, whose identities are not released, pay interest of just 0.50 percent on the emergency loans.

The Fed's weekly report also showed that banks are generally making less use of other programs designed to ease the financial crisis.

The average value of the central bank's holdings of short-term debt known as "commercial paper" dropped by nearly $300 million to $13.8 billion. The Fed's purchase of commercial paper is intended to increase the availability of financing that businesses use for crucial operations like payroll and supplies.

At its peak in January 2009, the Fed held almost $350 billion worth of commercial paper.

Banks also sharply reduced their reliance on short-term loans drawn from the Fed's "term auction credit" program. Those loans averaged $38.5 billion in the week ending Wednesday, roughly half the $75.9 billion outstanding the previous week. That is also much lower than the $406.8 billion daily average for the first week in January 2009.

Even with all the reductions, the Fed's balance sheet — a broad measure that tracks the central bank's lending — is almost $2.3 trillion, more than double the level before the crisis struck. The bloated balance sheet underscores the scale of efforts the Fed has undertaken to stabilize an economy hit with the worst financial crisis in seven decades.

Under one program, it is purchasing $1.25 trillion in mortgage securities from Fannie Mae and Freddie Mac. The purchases are intended to keep mortgage rates low and boost home sales.

The Fed held about $968.4 billion of the securities as of Wednesday, the central bank's report said, a slight drop in value from the previous week.

The Fed intends to finish its purchases by the end of March, though it hasn't ruled out buying more of the securities. It could come under pressure to do so if mortgage rates spike once the Fed's buying is complete.

The average 30-year mortgage rate fell to 4.99 percent this week, from 5.06 percent, mortgage giant Freddie Mac said Thursday. That's historically low but above the record low of 4.71 percent set in early December.

Critics on Capitol Hill and elsewhere have expressed concern that the Fed's extraordinary actions to fight the economic and financial crises could put taxpayers at risk by reducing the amount turned over to Treasury coffers.

But earlier this month the Fed said it paid a record $46.1 billion to the Treasury last year. The money came from the Fed's earnings from its lending activities. Still, the central bank faces risks that it could lose money by purchasing securities if it has to sell them after their prices had fallen.