The hijackers demanded and successfully negotiated the release of seven Palestinian terrorists held in Greek prisons.

[1] The six-person commando of hijackers, belonging to the Popular Front for the Liberation of Palestine (PFLP) and/or the Palestinian Popular Struggle Front (PSF),[2] demanded the release of seven Palestinians held in Greek prisons for three terrorist incidents, the El Al Flight 253 attack, the attempted hijacking of a TWA flight on 21 December 1969, and the 1969 Athens airline office attack.

[1] In response to the hijacking, the owner of the airliner, Aristotle Onassis, flew to Athens, and along with Stylianos Pattakos, the Greek Deputy Premier and Interior Minister, and Justice Minister Anghelos Tsou, attempted to negotiate with the hijackers, with all three offering to exchange themselves as hostages with the passengers.

[1][4] While their offers were rejected, it was through the mediation of the International Red Cross representative André Rochat at the Athens Airport,[1][2] that the Greek government eventually announced eight hours after the plane had landed that all the terrorists would be released within one month, while announcing that it had received assurances from Arab diplomats that Greece would never again be used for terrorist activities.

[1] The terrorists held in Greek prisons were eventually released in August,[6] despite objections from the Israeli government.