WASHINGTON (MarketWatch) -- Pending home sales rose in January to the highest level since Aug. 2013, the National Association of Realtors reported Friday. Its pending home sales index rose 1.7% from an upwardly revised December level, and sales were up 8.4% from Jan. 2014 levels. "Contract activity is convincingly up compared to a year ago despite comparable inventory levels," said Lawrence Yun, NAR's chief economist. "The difference this year is the positive factors supporting stronger sales, such as slightly improving credit conditions, more jobs and slower price growth." A sale is listed as pending when the contract has been signed but the transaction has not closed, though the sale usually is finalized within one or two months of signing. The NAR forecasts a 6.4% gain in existing home sales this year and a nearly 5% rise in median prices.