The firm, formerly Liverpool Victoria, has signed an initial two-year deal for the LV= Cup, with an option to renew for a further two years.
David Radford, LV= group marketing director, says the sponsorship is “a good fit” with its target audience.
The firm is already involved in rugby as sponsor of Twickenham-based Harlequins Rugby Union Club.
It also has a long-standing relationship with county cricket and recently extended its title sponsorship of the County Championship until 2012.
EDF announced it was dropping its title sponsorship of the tournament in July to concentrate on its partnership with the London 2012 Olympics.
The Anglo-Welsh tournament is jointly managed by the Rugby Football Union and the Welsh Rugby Union. It features 12 English Guinness Premiership sides and four Welsh regional clubs.