The final of the seventh series of the show will air on the BBC on Wednesday evening. The show will move to Channel 4 in 2018.
Currently TalkTalk holds the biggest TV sponsorship deal in the UK. The phone network provider pays about £10m a year to sponsor The X Factor on ITV.
Paul Hollywood is the only star of the show who will follow Bake Off from BBC to Channel 4, with Mel Giedroyc, Sue Perkins and Mary Berry all ruling themselves out of a move.