WASHINGTON - Sales of existing homes fell to the lowest level in nearly a decade in January while the median price for a home dropped for the fifth straight month.

The National Association of Realtors said Monday that sales of single-family homes and condominiums dropped by 0.4 percent last month to a seasonally adjusted annual rate of 4.89 million units, the slowest sales pace on records going back to 1999.

The median price of a home sold in January slid to $201,100, a drop of 4.6 percent from a year ago.

Sales were weak in all parts of the country except the Midwest, where sales posted an increase of 3.4 percent. Sales dropped by 3.6 percent in the Northeast, 2.1 percent in the West and 0.5 percent in the West.

Sales of both existing homes and new homes tumbled for a second straight year in 2007 as the housing industry was battered by a severe credit crunch that hit in August as major financial institutions began reporting multibillion-dollar losses on their investments in risky subprime mortgages, loans made to homeowners with weak credit.

The market for subprime mortgages has essentially dried up, and other types of loans have become harder to obtain as lenders have tightened their standards.

Lawrence Yun, chief economist for the Realtors, said he believed the housing market may be on the verge of bottoming out with a rebound expected to start toward the end of this year.

“Subprime loans and other risky mortgage products have virtually disappeared from the marketplace, and over the past five months, this has been reflected in soft but fairly stable home sales,” he said.

He said he expected demand to be bolstered in coming months by the action of Congress in the economic stimulus bill to raise the caps on the size of loans that can be backed by Fannie Mae and Freddie Mac and the Federal Housing Administration.