Doctors at Jerusalem Hadassah Hospital have begun an effort Monday morning to gradually bring Prime Minister Ariel Sharon out of a medically induced coma, a hospital official told reporters.

"The process has started," the official said, adding doctors hope the prime minister will gradually awaken and show signs of response.

Doctors said they will assess the response of the prime minister's pupils to light and his response to pain stimuli done by applying pressure to his hand or chest.

The awakening process, a critical stage in Sharon's treatment, was planned to be done by gradually reducing the medication that has kept Sharon in a medically induced coma almost since his hospitalization on Wednesday night.

The process is expected to take six to eight hours and even days for doctors to assess the extent of damage Sharon may suffer from the cerebral bleeding.

Doctors said they should have a good idea of the extent of the damage by the end of the day.

It is only after Sharon wakes up that his mental and cognitive capabilities can be assessed.

The decision to try to awaken Sharon was taken after a brain scan Sunday indicated that swelling of the brain had gone down,intra-cranial and blood pressure were within normal range, and that cerebral fluid was draining well.

Neurosurgeons said early Monday that the extent of Sharon's responses could vary from slight movements of the fingers or opening of the eyes, to a much fuller awakening.They have also cautioned that there is no guarantee that Sharon will wake up from the anesthesia.

"The patient does not always awaken," said Dr. Menashe Zaaroor, head of the neurosurgery department of Rambam hospital in the Israeli city of Haifa.