Landmark city centre building The Cube is to be put up for sale, the Post understands.
Market sources estimate it will fetch in the region of £60 million, representing a significant rise from the £37 million price when Tristan bought it from administrator PwC in 2012.
The Cube comprises 111,000 sq ft of office space and 64,000 sq ft of shops and leisure. There are more than 200 flats, which are not part of the sale process.
Since taking over the Cube, Tristan, working alongside city firm EDG Property, has purchased Fort Dunlop and recently revealed multi-million-pound redevelopment plans.
Neither Tristan or EDG Property would comment when approached by the Post.