Boston Properties is under contract to sell 875 Third Ave. for $370 million. Global Holdings Inc. has agreed to buy the 29-story, Class-A office building. The building has a total of 719,000 rentable sq. ft.

The sale will allow the Boston-based REIT to pare down its debt after its billion-dollar acquisition of 399 Park Ave. To that end, Boston Properties sold One and Two Independence Square in Washington, D.C., for $345 million in late November.

"The sale of 875 Third Ave. illustrates our ability to create and realize value through the sale of one of our premier properties," says Mortimer Zuckerman, chairman of Boston Properties.

The sale to Global Holdings is expected to close on or about the end of this month.

Once the sale is finalized, Boston Properties will own five Manhattan office buildings — Citigroup Center, 599 Lexington Ave., 280 Park Ave., Five Times Square and the Times Square Tower, which is currently under construction. All of the firm’s Manhattan buildings are centered within a five-block area bordered by 48th and 53rd streets in the heart of Midtown.