(Adds comments from CEO of Realtor.com)
* Number of U.S. homes listed for sale fell in May
* Amount of time properties are on the market dropped
* Median asking prices rose in May
WASHINGTON, June 13 (Reuters) - U.S. home buyers are snapping up houses at a faster pace this spring, but many homeowners remain reluctant to sell until prices edge up, data released on Wednesday showed.
The number of homes listed for sale fell 20.1 percent last month from a year earlier to 1.88 million, Realtor.com reported.
"You're seeing sellers sit on the sidelines in certain markets where there are homeowners with little to no equity in their homes. They aren't bringing their home to market," said Steve Berkowitz, CEO of Realtor.com, the official website for the trade group, the National Association of Realtors.
However, owners who put their homes up for sale raised their asking prices for a fourth straight month in May, a signal of growing confidence in the budding housing recovery.
The nationwide median asking price rose 1.9 percent from April to $194,400, the highest level in more than two years and up 3.2 percent from the year-ago level.
U.S. home prices are down more than 30 percent from their 2006 peak, but they appear to be bottoming out. The closely watched S&P/Case Shiller index of prices in 20 metropolitan areas gained 0.1 percent in March on a seasonally adjusted basis, though it was still down 2.6 percent from a year ago.
The volume of sales has also moved higher, with sales of previously owned homes hitting a two-year high in April.
"People are very selective of how and when they are putting their homes on the market, which are keeping prices reasonable," said Berkowitz. "The market is still fragile, and there's a bit of uncertainty."
The inventory of properties on the market often goes up during the spring selling season, but the number of homes for sale in May was down in most of the 146 markets tracked by Realtor.com. Half of them saw a 20 percent year-over-year drop.
The properties that are on the market are moving quicker. In May, the median time properties spent on the market dropped 9.8 percent from a year ago to 83 days.
"To get more inventory on the market will take improved consumer confidence. It will take the belief that prices have bottomed," said Berkowitz.
Asking prices fell in 24 markets on an annual basis, led by Reading and Allentown, Pennsylvania, where they fell 5.4 and 5.3 percent, respectively, and Milwaukee, where they were down 5.2 percent.
Phoenix reported the largest year-over-year jump in asking prices - 32.6 percent - followed by Santa Barbara, California, where they rose 30.1 percent, and Chattanooga, Tennessee, where they were up 24.06 percent.
The figures compiled by Realtor.com include sale listings from more than 900 U.S. multiple-listing services. (Reporting by Margaret Chadbourn; Editing by Bob Burgdorfer)