A storied downtown Boston office tower originally built by legendary developer Harold Brown has traded for $635 million.

Brookfield Properties sold 75 State St. to an LLC controlled by a real estate private equity firm, the Rockpoint Group, with offices in Boston, Dallas and San Francisco.

The sale closed on Sept. 20, according to information on file at the Suffolk Registry of Deeds.

The 1.16 million-square-foot tower was 98 percent leased as of early June. As part of the sale, Rockpoint is assuming a 2015 mortgage on the tower with a $310 million outstanding balance.