The Financial Times reported that Sky is in early stage talks with Liberty that would see the Comcast-owned company become both an investor and customer of the venture.
Last week, Liberty formally registered the venture as Liberty Fibre Ltd at Companies House.
Investment bank LionTree has been appointed to find new partners for the venture that would install new fibre lines outside the Virgin Media footprint.
Sky is in separate talks to use Virgin Media’s existing cable network which reaches around 50% of the country.
Last month, Virgin announced plans to offer a gigabit internet service to almost 15 million UK homes, while Sky has also announced a significant upgrade to its broadband platform with speeds up to 12 times faster than its standard broadband.
Meanwhile BT, TalkTalk and number of smaller players including the Goldman Sachs-owned CityFibre are also investing in full fibre networks.