According to Marketing Week, the six-figure deal will start on January 3 as Global Radio expands the Capital Radio brand into a new quasi-national station.
The relaunch will see Capital replace Global's six-strong pop music stations under the Galaxy stable, as well as the Red Dragon, Trent, RAM and Leicester Sound networks.
The new enlarged station is expected to reach an audience of around 6.5 million listeners every week across London, Scotland, the South Coast, Birmingham, Manchester, Yorkshire and the North-East.
Sponsorship from Virgin Media will feature on Capital FM's drivetime programme for an initial six-month trial period.
The cable operator, which recently recruited Nigel Gilbert as its first chief marketing officer, will use the sponsorship to promote its half-price bundle offer, followed by other promotions.
The agreement will also include online activity, such as a Virgin Media "takeover" of the Capital FM website homepage.
Yesterday, Virgin Media announced a raft of new 3D content coming to its video on-demand platform, including documentaries, animations and movies.