Hijackers holding about 50 hostages on a Kuwaiti airliner negotiated with PLO officials Tuesday, and Palestinian leader Yasser Arafat said he expected the standoff to end within hours.

The hijackers, who took over the Kuwait Airways plane a week ago, had warned earlier they were ready to die and dubbed the jumbo jet the "plane of the great martyrs." They condemned Kuwait for refusing to meet their demand to free 17 jailed extremists.Arafat, the chairman of the Palestine Liberation Organization, told reporters, "I expect the hijacking to end tonight," according to the state-run Kuwaiti News Agency.

Arafat, in Kuwait for a minisummit of Islamic nations, said the hijackers want to go to Algiers but he warned the PLO would halt mediation efforts if the hijackers kill more hostages. Two men already have been killed and tossed out of the parked plane.

"I told them (the hijackers) I will not continue my mediation in this atmosphere," the agency quoted Arafat as saying. "We are against these crimes, terrorist acts and hijackings."

He said the hijackers had asked to leave for Algiers and arrangements were being made "on this subject."

"Contacts were made with the brethren in Algiers so as to secure that the plane will go there and not to another place," said Arafat, who later left Kuwait for an unknown destination.

Arafat, who said he has been in constant touch with PLO negotiators at Larnaca International Airport, added, "What concerns us now is to release the hostages aboard the airliner.

Algeria has successfully mediated other hostage crises, most notably in the release of 52 U.S. Embassy personnel held hostage in Iran for 444 days in 1979-81.

The hijackers had said at 12:15 p.m. (5:15 a.m. EDT) "if we don't get fuel in 45 minutes you will force us to act in a different manner." Minutes before the deadline expired, two PLO representatives met with hijackers for 12 minutes at the door of the jumbo jet from a portable ramp.

Soon afterward, tension soared when a Greek C-130 aircraft painted in military camouflage colors arrived at the airport and parked less than 500 yards from the jumbo jet.

The hijackers, despite the plane's arrival, read a statement extending their deadline for a "short time." The tower told them the plane was carrying supplies for the families of Greek military personnel serving in Cyprus.

About 3 p.m. (8 a.m. EDT), a passenger who identified himself as Ahmed Al Ghabandi told the control tower in a radio message, "Please ask the Kuwaiti government to cooperate with the hijackers" and release 17 convicted Shiite Moslem terrorists, who are imprisoned in Kuwait for the 1983 bombings of the U.S. and French embassies.

"We are fine," said Ghabandi, who identified himself as chief of the Kuwait Fire Department. "We are being treated well but we are very tired.

"We have been here for 10 days," he said, apparently having lost track of time. "Please give our regards to our families."

Authorities said 52 people remain aboard the hijacked plane, including five to 10 hijackers and the three people who belong to the 1,000-member Kuwaiti royal family.

Kuwait Airways Flight 422 was taken over April 5 with 112 people aboard during a non-stop flight from Bangkok, Thailand, to Kuwait and diverted to Mashhad, Iran. Fifty-seven people were released during the plane's 80 hours in Mashhad. One hostage was released in Larnaca where the plane flew from Mashhad but two others were killed.