While existing-home sales were up 7.4% amid a surge of last-minute first-time homebuyers looking to close on purchases before the original expiration of the $8,000 tax credit, the national housing inventory hit a nearly four year low, according to the National Association of Realtors (NAR). The seasonally adjusted annual rate of existing home sales, including single-family, townhomes, condominiums and co-ops transactions, was 6.54m in November. That’s up from 6.09m in October and 44.1% higher than the rate of 4.54m in November 2008. The sales rate is the highest its been since February 2007, when it was 6.55m. “We expect a temporary sales drop while buying activity ramps up for another surge in the spring when buyers take advantage of the expanded tax credit, which hopefully will take us into a self-sustaining market in the second half of 2010,” said NAR chief economist Lawrence Yun. Housing inventory declined 1.3% at the end of November to 3.52m existing homes available for sale. That’s a 6.5-month supply of homes at the current sales pace, down from a seven-month supply in October. The national housing inventory is down 15.5% from where it was last year and the lowest since April 2006, when there was a 6.1-month supply. Yun said nearly all markets experienced a solid sales gain from one year ago, with the lone exceptions being the California cities of San Diego, Riverside, and Sacramento, where a shortage of lower-priced homes is limiting sales. The national median price for all types of existing homes was $172,600 in November, 4.3% below November 2008. Regionally, the Midwest experienced the greatest increase in existing home sales rate at 1.13m in November, an 8.4% increase from October and up 52.7% higher than November 2008. In the West, existing-home sales increased to an annual rate of 1.46m in November, up 10.6% from October and 28.1% from one year ago. The rate in the Northeast increased 6.6% month-over-month to 1.13m in November. That’s 52.7% higher than in November 2008. The smallest regional increase was in the South, where the rate of 2.39m in November was up 4.8% from October and 44.8% higher than last year. Write to Austin Kilgore.