Indian Wells - US tennis legend Billie Jean King said on Monday she is stepping away as majority owner of World Team Tennis (WTT), the innovative circuit she co-founded 42 years ago.

At a news conference during the Indian Wells hard court tournament, the 73-year-old great said she was selling her share in the league to Mark Ein, founder and owner of the Washington Kastles, and Fred Luddy, owner of the San Diego Aviators.

King will continue to serve as the owner of one of the league's teams, the Philadelphia Freedoms, as well as retain a minority role in WTT.

"This is an honor for me (and other owners) that we get to pass the torch to somebody we know will take us into the future, who will make us bigger and better than we could have ever imagined," King said.

"I am confident the league will continue to grow and prosper under Mark and Fred's leadership."

King founded World Team Tennis with the vision of providing equal opportunities for women and men in the sport and with giving tennis players the chance to enjoy playing in a team atmosphere.

Although it doesn't claim the cachet of the top tournaments on the ATP and WTA tours or the Grand Slams, it has attracted plenty of big-name players over the years.

King herself, Chris Evert, Martina Navratilova and Rod Laver all played in the early years. Andre Agassi, Andy Roddick, Pete Sampras and Serena and Venus Williams have also competed.

"Succeeding a pioneer like Billie Jean King is an incredible honor, and Fred and I are committed to significantly growing and building WTT 2.0 to thrill a new era of fans," Ein said.

Ein said the new owners hope to expand the league from its current six teams to 10 in 2018.