(Sharecast News) - BT Group slumped on Tuesday after competitor CityFibre announced a long-term broadband partnership with Sky.

Under the new agreement, Sky will offer its broadband to people on CityFibre's nationwide full fibre network.

Sky's full fibre broadband is expected to be available on CityFibre's full fibre network from next year. Longer term, this will include more than 1.3m homes in hard-to-reach areas through CityFibre's participation in the government's Project Gigabit Programme.

CityFibre chief executive Greg Mesch said: "This partnership with Sky is a huge vote of confidence in our business and has cemented CityFibre's position as the UK's third digital infrastructure platform.

"With demand for digital connectivity continuing to grow, CityFibre's network can provide the quality and reliability that people need and the infrastructure competition the UK deserves."

At 0920 BST, shares in BT were down 5.1%.

Danni Hewson, head of financial analysis at AJ Bell, said "CityFibre's modest scale and focus on rural areas suggest it shouldn't be a huge issue".