Billionaire Giannakopoulos took over the club in 2012 from his father and uncle and has overseen six league titles.

"My family has put into the team more than 450 million euros and we have brought top players and coaches. I'm tired of being the only person who gives money to the club," the 46-year-old owner of a pharmaceutical firm and a digital media group told a press conference.

"I will not be a member of any programming of the team. From today Panathinaikos are up for sale. If the team want my opinions they will have them. The team must leave the EuroLeague and go to FIBA," Giannakopoulos added.

They were created in 1919 and along with Aris Thessaloniki are the only side to have never been relegated from the top division.

The Athens side have won six EuroLeague championships, 38 Greek league titles, 19 Greek Cups, one Intercontinental Cup and two Triple Crowns.

"With the price of 25 million euros, someone buys the most successful club in Europe, a team that will go to an event that can make the sport profitable and that is why I believe if we go to FIBA we will not need such a disbursement," he said.

"As long as we are in the EuroLeague, the income is very limited and the need for funding is great," he added.

Giannakopoulos has often been an outspoken critic of the EuroLeague administration and had been fined numerous times.