A federal government-leased office complex in Herndon is under contract to trade hands for more than a quarter-billion dollars.

Boston Properties announced in its Q4 earnings report Tuesday evening it entered into an agreement to sell the New Dominion Technology Park for $256M. It did not disclose the buyer of the property, but it said it expects the deal to close this quarter.

The property, near the intersection of Herndon Parkway and Grove Street, consists of two four-story office buildings totaling 493K SF. Boston Properties said in Q3 it signed a 15-year lease renewal with the U.S. government for the entire 493K SF complex. The General Services Administration manages the leasing for most federal government agencies.

Boston Properties did not disclose which agency leased the Herndon property, but Google Maps and past reports indicate it is a counterterrorism center. The earnings report also said Boston Properties repaid roughly $27M in bond financing collateralized by the New Dominion Technology Park that was scheduled to mature in January 2021.

The deal comes after Boston Properties in January 2019 announced it sold the new Springfield office project it pre-leased to the Transportation Security Administration for $98M. That lease was one of five build-to-suit office deals Boston Properties closed in the D.C. area between July 2017 and March 2018.