The exiled shah of Iran is reportedly suffering from advanced cancer, and underwent tests in a New York hospital today.

According to State Department sources, the shah has a malignant tumor and a blocked bile duct. One source said the cancer has begun to spread through the shah's body and that he may have a short time to live.

State Department spokesman Hoding Carter said the shah was admitted to the United States "on humanitarian grounds" after a team of European and American doctors examined him in Mexico and found that he needed immediate hospitalization in a modern facility.

Carter reiterated the U.S. position that the shah has no claim to authority in Iran, where the new regime has urged that he be assassinated.

The State Department has kept the Iranian government informed of its discussions about admitting the shah, in an effort to avoid an angry reaction from Tehran.

The decision to admit the shah was closely held within the government. Carter said it came after "a significant deterioration in his condition in recent days."

Shah Mohammed Reza Pahlavi will be 60 Friday. He flew into New York's La Guardia Airport Monday night in a private jet, accompanied by his wife, Farah, about a dozen aides and two doberman pinschers.

He was driven immediately to New York Hospital-Cornell Medical Center, and arrived shortly before midnight. The shah occupies three private rooms on the 17th floor of the Baker Pavilion. His security men are guarding him, and the United States has not been asked to provide protection, the State Department said.

The threat of assassination has hung over the shah since he was deposed Jan. 15. The head of Iran's revolutinary courts, Sadegh Khalkhali, has called publicly for the shah to be killed, and the government has offered an all-expense-paid trip to Mecca to any successful assassin.

The danger of assassinatin, plus the fear that Americans in Iran might be taken captive to be exchanged for the shah, were among the reasons mentioned when the U.S. government made it clear that it thought the shah would be better advised not to take up residence in the United States.

Under heavy guard, the shah has moved from Egypt to Morocco to the Bahamas and then to Mexico during his exile. He has been seen in public rarely, one of the most recent occasions being when former president Richard M. Nixon visited the complex of villas the shah occupied in the Mexican resort town of Cuernavaca.

Chris Godek, an aide to Robert Armao, the 30-year-old American public relations man who carries the title senior adviser to the shah, said she could not confirm or deny the reports that the former ruler has cancer.

She said the shah walked from his plane to his car and walked under his own power when he entered the hospital.

Godek said there will be an announcement as soon as the shah's medical condition has been fully evaluated.

in Tehran, Ibrahim Mokalia, the official spokesman of the foreign ministry, said, "We have information that [the shah] is suffering from terminal cancer." He said Iran would send a doctor to New York to observe the shah's treatment.

The Iranian government has told Washington that it prefers the shah not to enter the United States. State Department spokesman Carter did not refer to Tehran's position, but took pains to say that there was no political significance to the decision to grant the shah and his party B2 (business) visas. The visas are reportedly open-ended.

Carter said, "It is clearly understood that he is in this country for medical treatment, and we expect that when it is finished he will go back [to Mexico]."