Mayor Wu signed a 10-year lease and cooperation agreement with the leadership of the Boston Unity Soccer Partners (BUSP) on Monday morning in a deal that Wu said will transform the outdated city-owned White Stadium into a state-of-the-art facility shared by Boston Public School student-athletes and Boston’s new pro soccer women’s team.

Work to prepare the site for a massive renovation project— including the demolition of parts of the current stadium— will begin in January, the mayor said. The deal commits that the facility will be ready for use for the start of the 2026 spring soccer season— with the full project completed by the fall of 2026.

Wu has come under mounting pressure after disclosures that the cost of modernizing the stadium has grown substantially in recent weeks and months, with an estimated $91 million contribution— up from $50 million initially— needed from city coffers.

The soccer team will fund “more than half of the construction costs,” Wu confirmed on Monday. It will also pay $400,000 in annual rent over a ten-year term— a fee that will rise 3 percent each subsequent year— and has agreed to share a portion of advertising, naming rights, and concession proceeds.

Boston Unity has also promised to contribute $500,000 to a “community annual fund” that will be “distributed to local organizations.” And one dollar from every pro soccer game ticket will be used to fund improvements to Franklin Park under the lease arrangement.

“Delivering excellent education for BPS students includes ensuring the fullest access to sports, arts, and enrichment of every kind across the city. White Stadium is a generational opportunity to anchor citywide youth sports, revitalize community programming, and bolster our beloved, historic Franklin Park–all while creating a home for the City of Champions’ newest professional team,” Wu said in a statement announcing the terms of the agreement, which were disclosed in detail during a press briefing on Monday morning.

The mayor called it the largest investment in BPS athletics since the stadium opened in 1949. She has devoted considerable political capital to the goal of finally addressing the stadium— which she called “run-down” — and promises of “incredible ripple effects across the entire community.

“Now that lease has been signed, we are going to move forward with site prep in the next couple of weeks and demolition set to follow in January,” said Wu, who said the construction would move ahead at a “pretty accelerated timeline” for a city project.

Highlights of the agreement include:

• BPS students will get use of the facility for “at least 700 programmable hours annually” and priority use of a new eight-lane track and facilities for track and field to host state track meets, including new field events such as shot put and pole vault for the first time; a new, natural grass field for BPS soccer, end of season football, and other BPS sports teams; new locker rooms, strength and conditioning spaces, sports medicine facilities, offices and space for coaching staff, and a student lounge.

The project will also include repairs to basketball and tennis courts outside the stadium, public restrooms accessible throughout the year, along with improvements to drainage, lighting, and walking paths in the park.

• Boston Unity Soccer Partners will be responsible for construction of the stadium’s West grandstand, along with “public restrooms, pro team spaces, scoreboard, stadium lighting, technology system, and the Grove area. The contract makes the city responsible for the East grandstand, student athletics spaces, the grass field, and the track.

Additionally, “Boston Unity Soccer Partners will be responsible for ongoing operations and maintenance for the team’s spaces and all the shared areas of the facility, including the field and track,” the agreement states.

• Financials: In addition to $400,000 rent per year (made monthly starting in the second season), BUSP agrees to pay the city 10 percent of in-stadium advertising revenues, 10 percent of field naming rights revenue, and 3 percent of concessions revenue.

● The pro franchise will set up a $25 million “construction escrow account” to “fund direct construction costs on the site and require City approval of expenditures. The escrow account cannot be reduced below $10 million until total project financing is secured.”

• The project is expected to create 500 construction jobs and 300 permanent jobs.

The city and soccer team say they will “establish a Supplier Diversity Advisory Committee to help ensure that Minority/Women-owned Business Enterprises (MWBE) ) are aware of available contracting opportunities and reach 50 percent MWBE participation in design, construction, and operations.”

● The pro team will be limited “to no more than 20 games per year (including playoff games) and one team practice in the week ahead of each scheduled game,” which “must start by no later than 8:30 p.m.; “affiliated programming may only start two hours prior to the game and must conclude by one hour after the game ends or 11:30 p.m., whichever is earlier.”

• Free “electric shuttles” from Orange and Red Line stations will be in place for pro team ticket holders “as well as from satellite parking lots on game days.”

BUSP will also fund a new Bluebikes station, secure bike parking, and a bike valet service; resident permit parking will be created near White Stadium with an “app-based parking system (via ParkBoston) for non-game visitors, including zoo visitors, golfers, and park permit holders.”