SEATTLE – A San Francisco firm closed a multimillion dollar deal last week on a valuable piece of property south of Safeco Field.    Valiant Partners of San Francisco bought the land from a Seattle businessman for $21.6 million, almost $3 million more than the land's assessed value. The deal for the parcel, which is a little more than three acres in size, closed on December 6. The land is located just south of the Safeco Field parking garage.   Valiant's deal comes as a well-placed source acknowledged a developer had approached the city about constructing an arena south of downtown near the two stadiums.   Another source close to the talks said the deal would include a “large private contribution”, but that nothing was concrete.   Valiant would not discuss the deal Monday or their plans for the property.  Aaron Pickus, a spokesperson for Seattle Mayor Mike McGinn, said the mayor's office is still evaluating an opportunity and would welcome the NBA’s return.   Seattle and Bellevue civic and city leaders have now privately discussed arena plans in recent weeks. Tacoma took the step of commissioning a study in September on the feasibility of renovating the Tacoma Dome for an NBA or NHL franchise.   The SuperSonics left Seattle in 2008. Since then, NBA franchises in Sacramento and New Orleans are playing through an uncertain future.The Maloofs, which own the Sacramento Kings, briefly discussed moving their franchise to Anaheim, Calif. The NBA has now given the city of Sacramento until spring to develop a new arena plan or the team may move.The New Orleans Hornets are currently owned by the league and has certain attendance and ticket thresholds in place to keep the team in the city. The NBA says it is still looking for a local owner for the franchise.   The NHL manages the Phoenix Coyotes hockey franchise which has battled through bankruptcy, and several reports have indicated the league wants a local investor soon or will look to relocate the team.