Dallas Mavericks owner Mark Cuban is working on a deal to sell a majority stake in the NBA franchise to the family that runs the Las Vegas Sands casino, a person with knowledge of the talks said Tuesday night.

The agreement would be in the valuation range of $3.5 billion and take weeks for the league to process, according to the person, who spoke to The Associated Press on condition of anonymity because details weren't being made public.

Cuban would retain control of basketball operations in the deal. NBA reporter Marc Stein was the first to report the potential sale.

The family of Miriam Adelson, widow of casino magnate Sheldon Adelson, announced earlier Tuesday it was selling $2 billion of her shares to buy an unspecified professional sports team.

Cuban said almost a year ago he was interested in partnering with the Sands. He has been a proponent of legalizing gambling in Texas, an issue that didn't make it out of the state Legislature in a biennial session that ended earlier this year.

The 65-year-old Cuban, who just announced he was leaving the popular business TV program "Shark Tank" after a 16th season next year, rose to fame quickly after buying the Mavericks in 2000.

Dallas was one of the worst franchises in pro sports in the 1990s, but turned into one of the best under Cuban, with a lot of help from star forward Dirk Nowitzki.

The Mavericks, who won the franchise's only championship in 2011 with Nowitzki leading the way, are worth $4.5 billion, according to Forbes magazine.