Sales of new U.S. homes fell 5 percent in January to their slowest pace in a year while the number of homes on the market climbed to a record high, according to a government report Monday that signaled further cooling in the housing market.

Sales of new single-family homes declined to a 1.233 million unit annual pace from an upwardly revised 1.298 million unit pace in December, the Commerce Department said.

January's sales pace was slower than expected. Economists had forecast new homes sales would ease to a 1.260 million unit rate from the originally reported 1.269 million unit pace in December.

The number of new homes available for sale at the end of January rose to a record 528,000. At the current sales pace, that represented 5.2 months' supply — the largest inventory since November 1996.

The U.S. housing market has begun to show signs of cooling after a five-year rally that shattered sales and construction records, and sent prices soaring more than 50 percent on average nationwide.

Home prices, however, have been more resilient, and economists chalk that up to stubborn sellers trying to cash out at the market's highs. For January, Commerce Department data show the median home sales price rose 4 percent to $238,100, for example.

New home sales fell in all U.S. regions but the West, which posted an 11.3 percent gain. Sales dropped 14.9 percent in the Northeast, 10.8 percent in the Midwest and 10.3 percent in the South.

The homes sales data is subjected to major revision as the statistics are estimated from sample surveys.

Click here to visit FOXBusiness.com's Real Estate page.