ST. PETERSBURG — Tom James' idea for an art museum has been a dream for years and the subject of speculation for months, but now it's an official plan.The executive chairman of Raymond James Financial announced Monday that he is under contract to purchase the first two floors of a building at 100 Central Ave. so the public can enjoy what his family and employees have privately enjoyed for years. The building was occupied by Florida Power/Progress Energy from 1998 to 2007 and Universal Healthcare from 2008 to 2013, until that company filed for bankruptcy. Above the space are six parking levels used by the city and One Progress Plaza, a nearby office building. The building's 133,600 square feet will showcase part of James' vast collection of Western and American Indian art. James has not released details about how the entire space will be used, only saying that about 60 percent of it will be used for the art museum itself. For a size comparison, the Salvador Dalí Museum in St. Petersburg has 66,450 square feet for all of its operations.The transaction is expected to close in October, according to a statement released by James, and the museum is tentatively scheduled to open in 2017.That date could make for a spectacular year for the arts in St. Petersburg. The American Arts and Crafts Movement Museum is also scheduled to open in 2017, a gift to the community from another wealthy collector, Tarpon Springs resident Rudy Ciccarello.With the existing Dalí Museum and the Museum of Fine Arts, St. Petersburg, the city would have four art museums. The central coastal region would boast nine, ranging from the John and Mable Ringling Museum of Art in Sarasota to the USF Contemporary Art Museum in north Tampa."This will be a major addition to our arts, cultural and economic development community," St. Petersburg Mayor Rick Kriseman, whose office has been working with James, wrote in an email. "I thank him for his generosity."James said in an interview with the Times in 2014 that he would commit up to $75 million of his own money to the project. The sales price was not disclosed Monday, and neither was information about the renovation and its cost.James, 73, remains an active leader at the company his father co-founded and which he grew into a giant in the financial industry, but much of the daily responsibilities have been turned over to other executives. He began collecting art as a student at Harvard University and has never stopped, developing an affinity for art glorifying the American West, its natural beauty and the culture and history surrounding cowboys and American Indians.He and his wife, Mary, also have a fine collection of art by Florida painters and sculptors, wanting to recognize and support their talent. Their collection numbers more than 2,500 pieces.Though it is owned by the couple, most of it is housed, and will remain, in the company's headquarters in the Carillon office park. Tours can be scheduled there, but it's not on public display for the most part. A small part of the collection did have a public showing in 2014 as part of "New Mexico and the Arts of Enchantment Featuring the Raymond James Financial Collection" at the Museum of Fine Arts.As many as 600 works would be exhibited in the new museum, which would also have gallery space for changing shows. The Jameses have been among the Tampa Bay area's most generous philanthropists for decades, giving millions to many causes. Tom James has served on the Dalí Museum's board of trustees and been active in the Museum of Fine Arts, and has a deep understanding of how a museum operates.He said earlier that he arrived at $75 million for the new museum because "it took $40 million to build the Dalí, so that's what I'm basing the building cost on. … I also plan to put $30 million to $35 million in an endowment."James, who wasn't available for an interview Monday, has said that he estimates the value of his collection to be between $20 million and $25 million. "We are very happy to be working with Tom James on this ongoing project," Kriseman wrote. "While our discussions are ongoing, I am excited and optimistic that we will see this deal to completion, and that St. Petersburg will be home to the extensive collection of Tom James."Contact Lennie Bennett at [email protected] or (727) 893-8293.