Yesterday, Thompson confirmed that his deputy director general Mark Byford is to leave the BBC in summer 2011 after 32 years of service. His post will be closed.
Byford's departure is part of the BBC's strategy to streamline its management team towards reducing its senior pay bill by 25% by the end of 2011.
The director general has now confirmed that Sharon Baylay, director of BBC Marketing, Communications and Audiences (MC&A), will also leave the BBC, and her post will be closed.
Baylay was appointed director of MC&A in May 2009 after joining the corporation from Microsoft Online Services UK, where she was general manager. She also currently serves as a non-executive director of BBC Worldwide, the corporation's commercial arm.
From April next year, BBC North director Peter Salmon and BBC People director Lucy Adams will continue in their roles, but step down from the executive board. They will instead join the new BBC Operating Committee.
The BBC's MC&A and People divisions will cease to exist as standalone divisions, but come under an expanded group led by chief operating officer, Caroline Thomson. The move is intended to enable the BBC to "realise further efficiency savings in support and management costs".
It was announced yesterday that Helen Boaden, director of BBC News, is to join the restructured board to represent BBC journalism, following the closure of the deputy director-general post. All changes to the executive board were approved by the BBC Trust.
Writing to staff, Thompson said: "My objective is simplification - simplifying reporting lines, simplifying structures and reducing the number of senior managers.
"No-one should doubt our continuing belief in the importance of the work done by these divisions and the crucial role they have to play in the future of the BBC."
After the changes, the BBC's executive board will include Mark Thompson and Caroline Thomson, as well as BBC Vision director Jana Bennett, director of Audio and Music Tim Davie, director of Future Media and Technology Erik Huggers, BBC News director Helen Boaden and group finance director Zarin Patel.
In his MacTaggart Lecture at the Edinburgh Television Festival in August, Thompson pledged to introduce a "faster and deeper" rate of change and reform at the BBC.
"Simpler structures, fewer layers, fewer management boards. We are committed to reduce senior manager numbers by a fifth by the end of next year. That's a minimum. If we can go further, we will," said Thompson.
He added: "The BBC does need to compete for the right people - but we also need to recognise how much the external context has changed both in commercial media and across the public sector. By the end of next year, the total senior management pay bill will reduce by at least a quarter.
"The actions we've already taken on pay and bonuses and a review of senior pension arrangements right now means that many of the BBC's top managers - including myself - will see their total pay fall, not by five or 10%, but by much more."