Blackfriars Investments has bought the former BP Amoco headquarters in Westgate, Ealing, W5, for £34m.
The 15,192m2 (163,500 sq ft) eight-storey office building, now known as Westgate House, was sold by Royal & Sun Alliance.
Blackfriars plans to carry out refurbishments to include a retail outlet, gymnasiums, video conference rooms and parking for 300 cars.
Gary Blatt, director of Blackfriars, commented: “The building will compare very favourably with the likes of Stockley Park at lesser rents and outgoings.”
Nigel Ruaux, assistant manager for business space at Royal & Sun Alliance, said: “We are delighted with the sale and wish Blackfriars every success.”
Anthony Green & Spencer represented Blackfriars. Insignia Richard Ellis acted for BP Amoco.