The 50% stake was purchased by Scripps Network Interactive - a Tennessee-based network which owns the Food Network and Cooking Channel.
BBC Worldwide owns the remaining 50% of UKTV, while being given the opportunity to increase it to 60%.
Last year Virgin offloaded its channels Bravo and Virgin 1, which were sold to Sky for £160 ($262) million.
With up to 36 million viewers a month, UKTV is one of the UK's largest broadcasters.
BBC Worldwide chief executive, John Smith, said
: "The new agreement we are developing will bring benefits to UKTV's audiences in the way they can consume content and will help to sustain UKTV's track record of growth."
Scripps chairman, president and chief executive, Kenneth Lowe, added
: "UKTV is a significant opportunity for Scripps Networks Interactive to participate in a thriving multi-channel, dual-revenue stream media business in one of the world's largest television markets.
"Making a solid investment in UKTV and entering into a strong partnership with BBC Worldwide reinforces our core international strategy which we believe will create significant long-term value for our shareholders."
It has also been reported
that Scripps will pay Virgin a further £100 ($164) million for the debt owed by UKTV.