Virgin Media TV customers will be able to watch BT Sport content after the two firms signed a three-year wholesale agreement.
Under the terms of the deal, Virgin Media's pay-TV customers will be able to bolt BT Sport 1, BT Sport 2 and ESPN on to their existing package.
They can sign up for access to the subscription service - which offers live Barclays Premier League football and Aviva Premiership rugby union, among other sports - for £15 per month.
And customers upgrading to Virgin Media's XL TV service will receive the BT Sport channels for no extra cost.
Dana Strong, Virgin Media’s Chief Operating Officer, said the firm is "excited" to announce its deal with BT Sport, which will make the "fantastic new channels" available to millions of Virgin TV viewers.
Similarly, Marc Watson, Chief Executive at BT TV, said his company is "delighted" to have signed a deal with Virgin Media.
He explained that this increases the potential audience for BT Sport to around three million UK homes.
"BT is rewarding its loyal customers with free sport and it is great to see Virgin Media immediately making BT Sport available to so many of their customers," he stated.
Mr Watson said BT has made "a large investment" in BT Sport, and the Virgin Media deal represents "an important commercial agreement" for the firm.
"We are keen to make our services as widely available as possible and to do so via wholesale arrangements. We are doing this with BT Sport," he added.
With BT having agreed a deal with Virgin Media, the firm's sport channels are now available across all the major TV platforms in the UK including cable, satellite and digital terrestrial television.
The three channels are also accessible online via a broadband connection.