Home values have remained steady for three consecutive months in Maine and the Portland area, according to the real estate firm Zillow Inc., reflecting a lack of catalysts in Maine’s economy.

According to Zillow, the median list price in Maine has been $199,000 to $200,000 over the past three months. In the Portland area, the median list price has stayed unchanged at $250,000.

“It’s not a surprise that the price is holding steady. That reflects the Maine economy being flat for quite a while,” said Charles Colgan, professor of public policy and management at the University of Southern Maine’s Muskie School of Public Service.

“Maine has been relatively flat on migration and economic growth, so things are going to stay flat for a while,” he said.

Colgan said he expects Maine’s real estate market and economic growth to be flat through 2012, with a possible increase at the end of the year.

Next year should show some growth as the state benefits from any pickup in the national economy, he said.

Zillow based its home value index on the median valuation for single-family homes, condominiums and cooperatives.

The National Association of Realtors said Thursday that sales of existing homes fell in May, down 1.5 percent from April, to an annual rate of 4.55 million units.

That was in line with analysts’ expectations. Nationwide, the median price for a home rose to $182,600 in May, up 7.9 percent from a year earlier and the highest level since June 2010.

Housing starts for single-family homes rose in May.

The U.S. Department of Commerce said construction of new homes in May rose by 3.2 percent from April on a seasonally adjusted annual basis, while building permits increased 7.9 percent.

“We know that real estate is location, so national numbers make it harder to identify regional trends,” said Tina Lucas, president of the Maine Association of Realtors. “Consumer confidence is increasing. That gives people more impetus to buy or sell, or buy their first home. That’s the biggest catalyst for making those decisions.”

In Maine, sales of single-family existing homes totaled 1,035, a jump of 32 percent from last year, according to the Maine Association of Realtors.

“The number of first-time home buyers is a big percentage of transactions,” Lucas said.

“People see the affordability index and increased sales volume and the prices are not going to last forever. People don’t want to miss out.”

Staff Writer Jessica Hall can be contacted at 791-6316 or at:

jhall@mainetoday.com