The buyer is also assuming the $389 million in debt for the properties, about the only type of portfolio available today, says Richmond McCoy, president and CEO of the company. "We've only been looking at properties with existing debt, it's extremely difficult to acquire or sell properties in this environment that do not have existing debt," he tells GlobeSt.com. "There's been a dramatic slowdown in transactions this year, and it will continue."

The REIT will still hold a part of the portfolio. Rubicon is paying $30 million for preferred equity have some ownership interest in the portfolio. The trust said in a statement that it will use the $90 million in net sale proceeds to reduce overall borrowing.

McCoy says the portfolio fit his company's strategy of buying well-leased assets. "We focus mainly on government-leased buildings, or properties used by colleges or healthcare providers, very sticky tenants who generally stay where they are for geographic reasons," he says. The portfolio, which is 98% leased, is 93% occupied by GSA tenants, McCoy says.