Venus Williams is shown during a Fed Cup World Group match on April 21. As new minority-stake owners of World Team Tennis, Williams and Andy Roddick will help steer the league’s growth. (Richard Graulich/AP)

Venus Williams and Andy Roddick have something new to add to the trophies and titles on their résumés: part-owner of World TeamTennis.

The former world No. 1 players have acquired minority stakes in the professional league co-founded by Billie Jean King. As such, they will have a role in steering its growth domestically and internationally.

“It was really important to Billie and to me to bring in young owners who are current, close to the players and have great ideas,” WTT CEO and Commissioner Ilana Kloss said in a telephone interview.

Both Williams and Roddick have played in the league for years. Their role as co-owners (each has a 5 percent share) won’t affect their playing status.

Williams, 32, is scheduled to play the first two home matches of the upcoming season for the Washington Kastles, who are bidding to tie the 1971-72 Los Angeles Lakers’ record 33 consecutive victories in their July 8 opener at Kastles Stadium on the Wharf. It will be Williams’s fourth season with the Kastles, who have won three of the league’s last four championships.

Roddick, 30, who retired from the pro tour following his 2012 U.S. Open campaign, returns for his seventh season with WTT and his first with the Springfield (Mo.) Lasers. According to Kloss, Roddick is interested in bringing a WTT franchise to his adoptive home town of Austin at some point.

Looking to the future, Kloss said that she would like to see the league expand from eight to 16 teams over the next five years.

“There are a lot of U.S. markets that don’t have professional tennis: Chicago, Seattle, Austin,” Kloss noted.

But the league’s more pressing goal is strengthening its eight existing franchises, Kloss said, citing Washington, Philadelphia and Sacramento as high-performing benchmarks.

“It would be great to have eight Washington Kastles,” Kloss said.

It has been a busy offseason for WTT, which added pharmaceutical company Mylan as its title sponsor and renewed deals with Geico and Wilson.

The league’s international ambitions could take several forms, from staging WTT events overseas to licensing the WTT model for full-blown league play on other continents.

It’s possible other current or former pros could join Williams, Roddick and the U.S. Tennis Association as co-owners of WTT, Kloss said. But Williams and Roddick are ideal business partners, she noted, given their long-standing commitment to WTT and the sport in general.

“We want to listen to them, learn from them,” Kloss said. “They’re both so current. And players respect them a lot.”