San Diego-based BioMed Realty Trust has refinanced a 2007 short-term line of credit, and plans to use a portion of the proceeds to acquire 600,000 square feet of life sciences space in Cambridge.

The 2007 line of crdit was entered into by a joint venture with a fund managed by Prudential Real Estate Investors.

Proceeds from the refinancing were approximately $203 million. Part of that was used to repay a portion of outstanding debt, of which BioMed’s share is approximately $41 million.

"Completing the refinancing of the existing secured acquisition and interim loan facility with our partner PREI(R) represents the achievement of another milestone in managing our debt maturities," said Kent Griffin, president and chief financial officer of BioMed.

For the fourth quarter, BioMed reported net income of $12.5 million, compared to $17.5 million in the same period a year ago, a 28.6 percent decrease.

For 2008, the trust reported net income of $64.9 million, compared to $72.5 million in 2007, a 10.5 percent decline.