An office tower that’s recently attracted new tech, life science and coworking tenants has been sold to Rockpoint Group, in its second big-ticket acquisition in downtown Boston in the past month.

Boston-based Rockpoint acquired the 1.1 million-square-foot 100 Summer St. for $806 million from Blackstone Group. Wells Fargo Bank provided a $470 million mortgage.

Blackstone took ownership of the 32-story tower as part of its Equity Office Properties portfolio acquisition.

After the departure of major tenants including law firm Nixon Peabody and tech security firm Rapid7, 100 Summer has rebounded with leases by Cambridge biotech company Ironwood Pharmaceuticals, coworking giant WeWork and its rival Industrious.

Newmark Knight Frank’s Boston-based capital markets team represented the seller and arranged financing.

Recent upgrades include a new lobby and amenity center, which contributed to 600,000 square feet in leasing activity in the past three years, Newmark said in a statement.

In September, Rockpoint Group completed a $635 million acquisition of the 1.16 million-square-foot 75 State St.