BSkyB has taken control of Open, the interactive TV service developed by Sky, HSBC, BT and Matsushita.
Through an all-share deal, the satellite broadcaster has now increased its share in Open from 32.5% to 80.1% after acquiring the 20% of Open held by HSBC and the 15% owned by Matsushita for £225 million and £196 million respectively.
BT's holding in the company has also been diluted from 32.5% to 19.9% after Sky undertook to cover the service's future funding requirements.
Sky is now planning to enhance the Open service, which has access to over 9 million consumers in more than 3.4 million homes.
Tony Ball, chief executive of BSkyB, said: "By increasing our shareholding substantially, we are set to create a strong new revenue stream and establish long-term value."