Sky is set to put up the price of its Sky Sports channels, raising the cost to BT Vision and Virgin of broadcasting live sporting events.
BT announced earlier this week that it will charge customers £16.99 a month for both Sky Sports 1 and Sky Sports 2, or £11.99 for one of the channels.
But the wholesale cost of the channels to BT is now set to rise to £19.07 in September.
Sky is also set to increase the retail price of its sports channels from £35 to £38 in September to cover the costs of a new three-year deal to broadcast live Premier League football.
The new deal cost Sky £1.623bn, compared with £1.314bn for the previous three-year deal but it does give the broadcaster the rights to 23 more matches.
These additional costs will be passed directly on to BT, following a ruling by the regulator Ofcom in March that would mean Sky would have to cut the price it charged rivals for its sports channels.
Ofcom said Sky would have to sell Sky Sports 1 and 2 for £10.63 a month each but after Sky’s price increase, the wholesale prices will increase to £13.42 – which is more than the price BT is selling the channels.
These are significantly higher than the prices BT is charging, and has led to questions about how BT will make money from selling Sky Sports.