It currently uses a number of agencies, including Mediaedge:cia, MediaCom and PHD in the UK.
It is understood that it may look to consolidate the media planning and buying account into one agency.
BBC Worldwide recently moved to boost its global ad sales team as part of its strategy to offer cross-platform sales for the first time.
Last month, Anne Goodman was appointed vice president of enablement and trade marketing. She moved from Microsoft where she was director of sales marketing for international markets.
Tim Baynes was appointed director of learning and development. He was also previously from Microsoft.
They both joined former Microsoft colleague Chris Dobson, executive vice president of global ad sales.
Last month, BBC Worldwide renewed a deal with YouTube to have BBC branded YouTube channels and short-form videos.
YouTube has also recently launched a trial of pre-roll ads around content from BBC Worldwide, Channel 4, Discovery, ITN and National Geographic.
A BBC Worldwide spokesman says talk of a media review is “speculation”.