Powell joined Bloomsbury in 1985, just two years after it was founded by ex-Sotheby’s specialists John Kerr, Frank Herrmann and David Stagg.
He is the latest in a series of high-profile departures from the clutch of businesses under the umbrella of subsidiary The Fine Art Auction Group. He follows Stephan Ludwig, former managing director of the interiors and antiques division, and Ian Goldbart of Noble Investments.
Since November 2013 Dreweatts Bloomsbury have been part of Stanley Gibbons, the venerable collectables dealership and parent company of both numismatists AH Baldwin and troubled dealership Mallett.
The auditors for Stanley Gibbons resigned in February saying they believe the 160-year-old firm is exposed to excessive risk. Gibbons are currently seeking to raise £10m in an emergency share issue.
