Jerry Reinsdorf, 89, purchased a controlling stake in the White Sox in 1981, but has never publicly revealed what percentage of the team he owns.

The young private equity mogul already has major stakes in three other professional sports teams — and he's building what's thought to be the most expensive home in Illinois history.

The Chicago White Sox announced Thursday that longtime owner Jerry Reinsdorf has reached a long-term investment agreement that establishes a framework for Justin Ishbia to obtain a future controlling interest in the MLB club, but not before 2029.