PARIS - Doctors at a French hospital known for its work with blood disorders are conducting tests on Palestinian leader Yasser Arafat, whose frail health is raising questions about how Palestinians would react to losing the only leader they've ever had.

Pale and exhausted, Arafat left his battered base in the West Bank for the first time in nearly three years early Friday to seek treatment at the Paris-area hospital.

The 75-year-old Arafat has been sick for the past two weeks, and blood tests have revealed he has a low platelet count - a possible symptom of leukemia or other cancers or a number of other maladies.

The ailing leader arrived on a French military jet at an airfield southwest of Paris and was taken by helicopter to the nearby Hospital d'Instruction des Armees de Percy. His wife, Suha, was at his side.

Specialists at the Percy hospital's hematology clinic - where patients ailing from blood disorders are treated - were conducting tests on Arafat, the French Defense Ministry said.

"He arrived in good health, conscious, smiling - happy to be in France," said Leila Shahid, the Palestinian envoy to Paris.

Doctors were likely to need at least several days before issuing any kind of diagnosis, she said. In stable condition, Arafat was already undergoing treatment for the low platelet count, Palestinian sources told The Associated Press.

"We have three crucial days ahead of us before we can get clear answers as to whether there is something wrong and if it is serious," said Mohammed Rashid, Arafat's personal financial adviser.

Palestinian Civil Affairs Minister Jamil Tarifi, who was on the plane with Arafat, said his condition was "good, thank God."

"He was normal," Tarifi said.

Palestinians were beginning to consider how their world would look without Arafat, the only leader they have known for nearly four decades.

Many watched their leader's departure with mixed feelings, frustrated by his corruption-tainted rule and failure to resolve four years of fighting with Israel. However, he has been a unifying force and many feared his departure could unleash a possibly bloody power struggle.

"He is the safety valve for everything here," said Imad Samara, 38, a teacher in Gaza City. "He is the father of all the Palestinians."

Senior Palestinian officials were to hold a first round of meetings on the situation Saturday. Arafat has persistently refused to appoint a successor and did not name a stand-in during his absence.

"We admit that things will not be easy," said Yasser Abed Rabbo, a former Cabinet minister and Arafat confidant, "but we will try our best for full coordination ... and we will consult with president Arafat on the important issues."

During Arafat's illness, Palestinian officials have blamed the flu and gallstones. But on Wednesday, he took a turn for the worse - collapsing and briefly losing consciousness - and doctors who rushed in admitted they didn't know what was the cause of the low platelet count.

On Thursday, Arafat's personal physician, Dr. Ashraf Kurdi, ruled out leukemia. But an Arafat confidant, Dr. Ahmed Tibi, said Friday that "at this point, no possibility has been eliminated." Tibi, an Israeli Arab legislator, said Israeli intelligence officials have speculated that Arafat might be suffering from leukemia and he indicated that Arafat might have some symptoms of the disease.

Platelets are blood components that aid in clotting. A low count can be caused by many medical problems, including bleeding ulcers, colitis, leukemia and lymphoma, liver disease, lupus and chickenpox.

Hours earlier, Arafat had a somber departure from his Ramallah headquarters, seen off by a few hundred loyalists gathered on a rain-slicked tarmac. At daybreak, Arafat, wearing a gray fur hat and an olive-colored jacket, was helped into a Jordanian military helicopter.

Israel long refused to guarantee that if Arafat leaves his Ramallah base he will be allowed to return - a refusal that kept the Palestinian leader pinned down in his compound. But Israel, concerned it would be blamed if his health condition worsened, lifted the ban on Thursday and promised to allow Arafat to return.