A Back Bay office building that’s 98 percent leased to 38 companies has been acquired by a joint venture of Investcorp and Brickman for $128 million.

Newmark Knight Frank represented seller Manulife Investment Management, which bought the 184,643-square-foot tower at 535-545 Boylston St. in 2016 for $100.5 million.

During its ownership period, Manulife invested nearly $5 million in common area upgrades and building improvements.

“535-545 Boylston Street features a highly coveted corner location in the exclusive Back Bay, where such offerings are scarce,” Newmark Vice Chairman Edward Maher said in a statement. “In addition to its proximity to local icons such as Copley Square, the Trinity Church and Newbury Street, the asset is just two blocks from what will be the ultra-luxury Raffles Hotel & Residences’ first location in North America.”