Sonoma County’s housing market has gotten off to its slowest start in six years.

Buyers purchased 260 single-family homes in February, according to The Press Democrat’s monthly housing report compiled by Pacific Union International Vice President Rick Laws. Sales fell 11 percent from a year earlier.

For the first two months of the year, buyers have purchased 535 houses. That is the lowest number since 347 homes were purchased in 2008, a time when prices were tumbling sharply.

“Without a doubt we’re off to a slow start,” Laws said.

Experts say housing is still going through a transition in the aftermath of a historic housing crash.

“The market has been driven by the investor buyer,” said economist Christopher Thornberg of Beacon Economics in Los Angeles.

Over the last year, the investors have pulled back, he said. Eventually sales will be spurred more by the “move-up buyer” who is selling one home and buying a more-expensive property.

“We’re in between these two waves,” Thornberg said.

February’s median home sales price declined 2 percent from January to $449,825. The median remained 18 percent greater than a year ago.

During the last decade, the county’s median price reached a record $619,000 in August 2005, before falling to a low of $305,000 in February 2009.

Agents said buyers remain on the hunt for homes this winter but sales are constrained by a continued lack of supply.

“It’s just remarkable how the inventory has shrunk,” said Mike Kelly, an agent with Keller Williams in Santa Rosa.

February ended with less than 600 homes for sale, slightly more than a two-month supply of inventory at the current sales pace. That remains considerably lower than the roughly six-month supply that experts say is needed for a balanced market.

The lack of inventory was blamed for the slowest February sales in six years for the entire Bay Area.

The nine-county area reported 4,963 houses and condominiums sold last month, a decline of 8 percent from a year earlier, according to real estate information service DataQuick.

While citing various factors for the slower sales, DataQuick President John Walsh said in a statement that “clearly the main culprit is an inadequate supply of homes for sale.”

The Bay Area median sales price last month increased nearly 3 percent from January to $540,000. The median increased 33 percent from a year earlier.

— Robert Digitale