Leeds United chairman Andrea Radrizzani is selling his stake in the club.
The Italian has agreed a £170m deal with 49ers Enterprises to sell his majority shareholding to them.
The previous agreement was worth about £400m - but negotiations restarted following their drop to the second tier.
A club statement read: "Leeds United can confirm an agreement has been reached between Aser Ventures and 49ers Enterprises for the purchase of the club.
"Both parties continue to work through the details, and further updates will be provided soon. All of our focus remains on a quick return to the Premier League."
Radrizzani headed a consortium which bought Serie B club Sampdoria last week.