Dallas Mavericks owner Mark Cuban is preparing to sell the majority of his stake in the NBA team to a family that runs the Las Vegas Sands casino company, a person familiar with the matter said Tuesday.

The deal would be valued at around US$3.5 billion. It will take Silver Circuit several weeks to process the transaction, according to the person who spoke to The Associated Press on condition of anonymity because the information has not yet been made public.

Cuban would retain control of basketball operations under the agreement. Journalist Marc Stein was the first to report this potential sale.

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

Cuban indicated almost a year ago that he was interested in a partnership with the Sands family. He is a proponent of legalizing sports betting in Texas, an issue that was not addressed by the state Legislature during a biennial session that ended earlier this year.

The Mavericks were one of the worst organizations in professional sports in the 1990s, but that changed dramatically under Cuban’s leadership, with the help of Hall of Famer Dirk Nowitzki.

The Mavericks, champions in 2011, are worth 4.5 billion according to Forbes magazine.