Mr Dyke, 47, who resigned as chief executive at LWT in February 1994 after it was taken over by Granada in a hostile £765m bid, will take up his appointment on 1 March.
Mr Dyke will be responsible for expanding the group's television interests worldwide. Mr Dyke last night cited India and China as two areas of tremendous television potential.
He said owning television libraries and programming rights would be increasingly valuable in the future.
Under his leadership, LWT developed successful new programmes such as London's Burning and the Hercule Poirot series.
It is understood that talks have been going on between Mr Dyke and Pearson for over six weeks after he was approached by head hunters Frank Barlow, Pearson's managing director, said: "We admire what Greg has already achieved in a distinguished career in UK television."
Pearson's television subsidiary's interests include Thames Television, Britain's biggest independent producer of television programmes, and minority stakes in BSkyB (14 per cent), in the UK Gold (15 per cent) and UK Living (15 per cent) channels, and in YorkReuse content