CONCORD — A professional soccer stadium could be the anchor for a downtown development with hotels, shops and a convention center, but only if BART agrees to play ball.

Walnut Creek developer Mark Hall, whose business empire includes hotels, restaurants, residential and commercial projects, has expanded into the world of professional sports.

Hall Sports Ventures recently acquired the rights for an East Bay franchise of the United Soccer League, a Division II professional league with 33 teams, including the Sacramento Republic FC, Fresno FC and the LA Galaxy II.

With the Oakland Raiders leaving for Las Vegas, the Golden State Warriors moving to San Francisco and uncertainty about where the Oakland A’s will build a new stadium, Hall said he believes there is “an opening and an opportunity here for a professional team, and soccer is definitely on the way up.”

Hall’s stadium complex proposal revolves around the city’s vacant 3-acre former redevelopment agency property that is next to the downtown BART station and bounded by Oak, Laguna, Galindo and Mt. Diablo streets.

The project includes a 15,000- to 18,000-seat soccer stadium that could be used for football, lacrosse and rugby and also could be converted into a 24,000-seat venue for concerts or events; two hotels with a total of 650 rooms; a 150,000-square-foot convention center; retail space and housing.

Although Hall said the stadium would fit on the city’s land, to be feasible the project also would include BART-owned property.

Easy freeway access, abundant parking, and proximity to BART and Todos Santos Plaza make downtown Concord an ideal location for a stadium, according to Hall, who contends the proposed mixed-use development would generate tax revenue, create jobs and act as a regional draw for visitors, businesses and new residents.

“A well-conceived stadium complex can become a game-changing economic generator for the right area,” Hall wrote in a Jan. 10 letter to the city.

“We seek a community that will be supportive of these goals, appreciates the unique nature of the sport of soccer, both for its growth potential, as well as its cross-cultural dynamics, and will work actively with us to make this vision a reality.”

The soccer stadium project and USL team fit with another of Hall’s ventures — the Shadelands SportsMall athletic training center in Walnut Creek. In addition to housing swimming, basketball, gymnastics, yoga, baseball, volleyball and taekwondo programs, the SportsMall will include Copa Reál, Hall’s high-tech soccer training facility.

Hall recently made his pitch for an exclusive negotiating agreement with Concord for the stadium master development to the council’s Policy Development and Internal Operations Committee, made up of Mayor Edi Birsan and Councilwoman Carlyn Obringer, who were enthusiastic about the project.

Obringer said the stadium complex would address the need to ensure that the downtown continues to grow and thrive even as the city develops the Concord Naval Weapons Station.

Birsan was characteristically blunt, “I think it’s rather simple — let’s go get this.”

City staffers will work with Hall Sports Ventures to draft an exclusive negotiating agreement or memorandum of understanding to present to the full council. If council members sign off on the agreement, Hall plans to determine the feasibility of the project and pursue a deal with BART.