Eli Broad has chosen a downtown Los Angeles site to build a museum for his contemporary art collection after local officials on Monday agreed to lease him 2.5 acres of county-owned land.

The Broad Collection, a museum of contemporary art, will be built on Grand Avenue next to the Walt Disney Concert Hall. World-renowned architecture firm Diller Scofidio + Renfro was chosen as designer. Museum construction could begin in the spring and be completed by late 2012, the foundation said, though the parking garage and other preparatory work could begin as soon as October.

The museum, with 50,000 square feet of sun-lit display space, will house a 2,000-piece collection that includes works by Jean-Michel Basquiat, Salvador Dali and Joan Miro.

“Our heart is on Grand Avenue in downtown Los Angeles,” said Eli Broad, an avid booster of downtown revitalization. “This is our gift to the city that has been so good to us. We want to make great works of contemporary art accessible to the broadest public, and we can think of no better location than in the center of the contemporary art capital of the world.”

The billionaire philanthropist’s announcement came after the Los Angeles Grand Avenue Authority, a city and county joint powers authority, approved a plan to lease the land to Broad, who was considering a Santa Monica site.

Broad will finance construction, expected to cost up to $100 million, and contribute $200 million toward its operation. He will pay the county $7.7 million for a 99-year ground lease.

The complex will become the headquarters of the Broad Art Foundation, which plans to lend parts of the collection to museums around the world. It also will include a lecture hall and archive for scholars and curators.

The Broads, who already donated $60 million to build a contemporary art museum named for them at the Los Angeles County Museum of Art, have spent three years of evaluating sites in Los Angeles, Santa Monica and Beverly Hills.