SAN FRANCISCO - The University of Pacific will return to the West Coast Conference more than four decades after leaving the league.

Pacific formally accepted an invitation Wednesday to leave the Big West conference and become the 10th school in the WCC. The Tigers will officially join the WCC on July 1, 2013, and start play in nine sports in the 2013-14 academic year.

"It's a very big day," Commissioner Jamie Zaninovich said in a phone interview after the welcoming news conference in Stockton. "Everyone is excited to welcome Pacific back. They're a great fit and add a lot of value for us. The time was right to add a 10th school now."

The WCC had recently expanded to nine schools when BYU officially joined last summer. By adding a 10th team, the league can go back to having travel partners in sports like men's and women's basketball.

Zaninovich said no final decisions have been made in terms of travel partners or scheduling but said there will be an 18-game league schedule in basketball. That should be beneficial to many of the schools that sometimes struggle to find Division I opponents, especially for home games.

The most likely travel option may be to have Pacific partner with one of the three Bay Area schools: San Francisco, Santa Clara or Saint Mary's. With Gonzaga and Portland as partners in the Northwest, and Loyola Marymount and Pepperdine both in the Los Angeles area, BYU would likely team with San Diego as the fifth set of partners.

The schools also must decide whether to change the format of the conference basketball tournament, which currently gives the top two teams in the regular season byes until the semifinals.

The WCC got three teams into this year's NCAA men's basketball tournament in conference champion Saint Mary's, Gonzaga and BYU, and two teams into the women's tournament in champion Gonzaga and BYU.

With recent on-court success and expansion raising the profile of the league, Zaninovich said it is uncertain whether it still makes sense to "protect" the top regular season teams.

"That will be an important discussion," he said. "It's a little different conference than when that model was put in play. We'll have to decide how much to reward the conference season versus other models."

Pacific was a founding member of the California Basketball Association, which later became the WCC, in 1952-53 and remained in the conference until 1971.

Pacific has had success in men's basketball recently, going to three straight NCAA tournaments from 2004-06. The Tigers won first-round games the first two years before losing in overtime to fourth-seeded Boston College in the first round in 2006.

Pacific also won two national championships in women’s volleyball in the 1980s.

“We feel that Pacific is coming home by joining the WCC, where we have such a rich history,” athletic director Ted Leland said. “We look forward to competing with this amazing set of institutions.”

Gonzaga athletic director Mike Roth said the addition of Pacific is welcome from a scheduling standpoint.

“We just experienced a basketball season where we saw how cumbersome it can be to try and schedule a nine-team conference and at the same time try and be fair to all institutions,” Roth said.

Roth added Pacific will be a good addition to the conference.

“I’ve been the athletic director at Gonzaga for 15 years, and Pacific has always been a part of expansion talks,” Roth said. “Ted Leland is one of the most respected individuals in intercollegiate athletics and with Ted’s commitment to Pacific in becoming the full-time athletic director, I think the conference is confident Pacific will continue to grow athletically.”