Nine Entertainment has purchased the remaining 40 per cent stake in Millennial news website Pedestrian TV, valuing the business just shy of $100 million, making it one of Australia's biggest ever digital media deals.

The TV network, which is also in the process of acquiring a majority share in Fairfax Media, paid $39 million for the remaining 40 per cent, only three-and-a-half years after buying the initial 60 per cent for about $10 million.