Webb was tipped to succeed Clive Milner, The Times' managing director, following the news that Milner would be focusing on his News International group role.
However, Webb lost out to the general manager of Times Newspapers, Paul Hayes, this week, and has left the company with no job to go to. He was immediately replaced by the commercial director of The Times, Mike Gordon.
Webb joined News Group Newspapers as its director of advertising in 1995.
Before this, he spent 19 years at media agencies such as Optimedia. He is also the non-executive chairman of the Newspaper Marketing Agency.
NI sources say Webb had considered himself ready for a step up, and he is already being linked to the vacant managing director's position at Mirror Group Newspapers. However, Webb's terms of departure are unlikely to permit him to join a rival newspaper group for at least six months.
Webb's departure follows a restructure to the company's top-tier management, which is being carried out by the News International executive chairman, Les Hinton.
As part of the reshuffle, Milner will drop his duties at The Times in order to focus on his position as News International's group managing director, and will take on the responsibility of overseeing Times Supplements.
Meanwhile, Hayes will be succeeded as The Times' general manager by Andrew Mullins, who was the marketing director for The Times and The Sunday Times.
The restructure also sees Ian Clark, the commercial director of NGN, take the position of advertising director of The Times.
- Headliner, page 9.