Americans stepped up their purchases of new homes in July to the fastest pace in nearly nine years, as low mortgage rates and a steady job market are fueling a real estate surge.

The Commerce Department says new-home sales jumped 12.4 percent last month to a seasonally adjusted rate of 654,000 units, the strongest level since October 2007. Demand has eclipsed the pace of construction. Just 4.3 months' supply of new homes is on the market, down from 5.2 months a year ago. Sales have climbed 12.4 percent year-to-date.

Purchases shot up 40 percent in the Northeast and 18.1 percent in the South last month. They increased slightly in the Midwest and stayed unchanged in the West.

July's median sales price dipped 0.5 percent from a year ago to $294,600.