Yasser Arafat telephoned colleagues in the West Bank, read telegrams from well-wishing world leaders, ate cereal and sipped tea Sunday, his aides said -- signs that the Palestinian leader's health may be on the upswing after three days of urgent treatment for an undisclosed illness at a French military hospital.

There was still no explanation for what caused the recent deterioration in his condition, although Palestinian officials said Arafat's low blood-platelet count is not due to leukemia.

Doctors have not said what might be causing the deficiency, although Palestinian Foreign Minister Nabil Shaath said all types of cancer had been ruled out. However, no doctors or other specialists have publicly confirmed that.

Arafat's doctors in Ramallah said last week that toxicology tests ruled out poisoning.

The 75-year-old Arafat's condition has improved markedly since he was rushed Friday from his besieged Ramallah headquarters in the West Bank to the hospital southwest of Paris, Palestinians said.

"He's much better; he's really much better, and he's more cheerful," Shaath said. "He's less tired, and we are awaiting a final assessment by the French doctors about the diagnosis."

Palestinian officials gave conflicting reports on when results from further tests were expected. Palestinian Cabinet minister Saeb Erekat said a medical report would be issued by early Tuesday. Mohammed Rashid, a close Arafat aide, said results were due Wednesday.

Platelets are blood components that aid clotting. A low count indicates a possible problem with the bone marrow, where blood cells are made. There are many causes of platelet decline, ranging in severity from minor to life-threatening.

French physicians gave Arafat a platelet transfusion after his transfer to the Hopital d'Instruction des Armees de Percy, a military training hospital that specializes in blood disorders and trauma care.

Arafat has been ill for two weeks with what was initially described as bad flu. Arafat spokesman Nabil Abu Rdeneh said Arafat is expected to recover.

"He is not suffering from any serious problem -- his situation is curable; he will recover very soon. It is better than expected," Abu Rdeneh said.