P.O.K. (from the initial letters of Panathinaikos, Olympiacos and Konstantinoupolis-AEK-) was a coalition, a kind of an athletic trust, of the three main football teams of the Greater Athens area (the "big three") which lasted until the mid 60's. The term dates to in 1927, when Olympiacos F.C., Panathinaikos F.C. and AEK F.C. withdrew from the Greek Championship after disagreements with the Hellenic Football Federation (HFF), mainly over the championship's financial status. The HFF determined that league's revenues would be equally divided between all teams that participated. Olympiacos, Panathinaikos and AEK did not agree with this, and formed a group called P.O.K. During that season, they played friendly matches with each other.