Brydon departed abruptly this week and the Standard has yet to appoint a replacement. Stephen Lafferty, the newspaper's head of trading, is expected to run the ad operation until the post is filled.
Rosemary Gorman, the head of client sales at the Daily Mail, is tipped to replace Brydon. The Standard confirmed Brydon's departure but refused to comment further.
Brydon, the former managing director of CIA Medianetwork, joined the Standard in October 2002. He was involved in introducing a controversial ad policy, which saw the Standard give away free space to agencies that committed to the title. The policy was dismantled by Bert Hardy, the managing director of the Standard, when he took over last September.
Since then, the Standard has found the going tough owing to circulation and readership declines. However, the title's sales rose by 8.2 per cent during May after a revamp by its editor, Veronica Wadley.