BOSTON—The booming life sciences sector in Cambridge and GreaterBoston is causing some companies to look to other neighboringmarkets for suitable space.

With vacancy rates in the single digits in Cambridge and onlyapproximately 600,000 square feet of available lab space in theprime markets of Boston, Cambridge, Watertown, Medford, Somervilleand Charlestown, life sciences companies are making sacrifices,according to Evan Gallagher, executive vice president and directorof life sciences of brokerage firm NAI Hunneman.

"It is pretty dire out there," says Gallagher, who representsventure capital companies as well as entrepreneurs who aresearching for lab space in the Boston area. "I think we are inhistoric times right now. We are at a 1% vacancy rate and droppingin the Cambridge market for lab space." He adds that a host offirms are competing for every available space in the prime lifesciences and biotech markets here. "It's a challenge everywhere,"Gallagher says.