This is not the first office building John Buck Co. has acquired here: last fall it purchased 1620 L St., for $61 million. That purchase was among the last to close before the DC investment sales market went all but dark.

John Buck's experience in the DC market was one factor that brought the sale to closure, Ryan tells GlobeSt.com. ""It helped that they had been one of the groups to acquire a property here recently--they have a proven track record and showed their ability to close a deal."

Another factor, he says, is the fact that the building is a core acquisition, occupied by long-term tenants. "It is safe to say that downtown Washington properties are still attracting a large amount of interest," Ryan says. CBREI sold the building to generate liquidity in order to implement some other strategies across their portfolio, he adds.

The 1501 M St. trade lends credence to the theory--or as some might say, wishful thinking--that the market may be coming back to life with buyers and sellers starting to agree on building valuations and price. Last week another office deal also closed--MRP Realty acquired a 212,000 square foot office building in the Clarendon, VA submarket for $72 million. The week before, Franklin Street Properties, a real estate investment trust in Wakefield, MA, acquired an office building in Chantilly, VA for $29 million.