Virgin Media is reportedly lobbying for Sky to reduce its stake in ITV from 17.9% to 5%.
Earlier this week, the Competition Commission ruled that Sky's current stake restricted competition and was "against the public interest".
The Commission will present its full report to the Secretary of State in January, with Sky likely to be required to sell its stake or reduce it in order to restrict its influence over the broadcaster.
Insiders have told Broadcast that while Virgin Media would prefer Sky sold its entire stake, it will probably campaign for Sky to reduce it to 5%.
Reducing to around 10% would mean Sky would remain ITV's biggest shareholder but with much less influence. Brandes Investment Partners, ITV's next biggest shareholder, currently owns 8.4%.
