P.O.K. (from the initial letters of "Podosferikes Omades Kedrou", Greek: Ποδοσφαιρικές Ομάδες Κέντρου, English: Central Football Teams) was a coalition, a kind of athletic trust, of the three main football teams of the Attica (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 Athens 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.