Sales of existing homes edged down a slight 0.1 percent in January as attractive mortgage rates continued to support strong demand in the housing market, a real estate trade group reported Friday.

The National Association of Realtors (search) said existing single-family homes and condominiums were sold at a seasonally adjusted annual rate of 6.80 million units in January, down from a revised 6.81 million units in December.

For the first time, the Realtors included sales of condominiums in their monthly report of single-family homes. The median price for a home sold was $189,000 in January, an increase of 10.5 percent from January 2004.

The strength in January came from sales of condominiums which rose by 2.3 percent to an annual rate of 858,000 units. This offset a 0.5 percent decline in sales of single-family homes which dropped to 5.94 million units.

Around the country, the strength came from the South, where sales rose by 3.5 percent and the West where sales were up 0.6 percent. Sales dipped 3.5 percent in the Northeast and 5.2 percent in the Midwest.

Realtors chief economist David Lereah said even with the small overall decline in sales, demand for homes remained strong. In fact, the supply of homes fell to a record low of 3.7 months, the amount of time it would take to sell all of the homes on the market at the January sales pace.

With release of the January report, the Realtors revied the housing data going back to 1999. Those revisions resulted in reductions in overall sales for those years. However, the levels still represented record sales for the last four years.

The Realtors said they had decided to include data on condominiums in the monthly sales report because of improvements in the reliability of the information on condominium sales, which account for 12 percent of sales in the existing home market.