A management cull by director-general Mark Thompson has resulted in the closure of Baylay's post.
In addition, the MC&A division will no longer stand alone but join an expanded operations group led by chief operating officer Caroline Thompson, along with the People division.
As a board member Baylay, who is due to go on maternity leave around the end of November, is entitled to a maximum notice period of 12 months and one month redundancy payment for each year of service.
Her departure would leave Helen Normoyle, director of marketing, as the next most senior marketer at the corporation.
The changes come amid a review of the corporation's marketing agency roster started at the beginning of the year. A concurrent review of its marketing function has reduced its budget to £89m in 2010/11, down £4.3m from the previous year.
In today's changes Thompson has also slimmed down the executive board by moving Peter Salmon, director of BBC North, and Lucy Adams, director of BBC People, to a new operating committee.
The cull yesterday progressed with the announcement of the departure of Mark Byford and the disappearance of his deputy director-general role.
Baylay took the role in February 2009, having previously worked at Microsoft as general manager of online services in the UK. She was paid a total of £345,000 in the 2009/2010 financial year.
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