Ayatollah Mohammed Kazem Shariatmadari, the highest ranking Shiite Moslem leader living in Iran, said today the immediate formation of an "Islamic revolutionary council" to oppose the new civilian government would risk tough army reaction and more violence in the strife-torn country.

The statement was the closest the 76-year-old religious leader has come to criticizing Ayatollah Ruhollah Khomeini, the exiled religious leader who has been pushing his concept of a revolutionary council as a first step toward an Islamic republic that would "sweep away" the fledgling administration of Prime Minister Shahpour Bakhtiar.

The conflicting position raised the specter of an open split in religious opposition ranks between conservatives and hard-liners if Khomeini goes through with his plan unilaterally. The political opposition has already fractured somewhat because of Bakhtiar's agreement to head a government under a regency council representing the monarchy.

Even as marchers chanted slogans against Bakhtiar during a massive opposition demonstration in this Shiite holy city 90 miles south of Tehran, Shariatmadari refused either to criticize or praise the new government.

"I do not have any opinion on the Bakhtiar government," the plump, white bearded ayatollah (a Shiite title meaning "reflection of God") said in an interview at his house. "I neither support it nor condemn it."

But in an indication of his concern, he added: "In considering the present situation of the country, I'm afraid if the government is condemned, the country will enter into more violence and trouble. I fear that if the Bakhtiar government collapses, there might be nobody around to take over."

He said that in addition to the possibility of provoking a mmlitary coup, his main concern over the proposed Islamic government was that it should be established legally, have full domestic support, and be recognized by other countries.

Shariatmadari said he was waiting for further details from Khomeini about his revolutionary council proposal before giving an opinion on it.

"There is a possibility of a reaction from the army if the Islamic revolutionary council is established in Iran," Shariatmadari said. "Recent events in Ahwaz and Dezful show that there are some people in the army who are not happy." He referred to two towns in the southwest Iranian oil-producing region where army troops angered by Shah Mohammad Reza Pahlavi's flight into exile Tuesday took revenge by firing on demonstrators and townspeople, killing at least 40 persons.

Shariatmadari said any Islamic council should think of a way to form a government accepted inside the country by the people and the army and recognized outside the country as a legal government.

He said his aides "are consulting experts on international law" to determine how an Islamic revolutionary government could be set up legally and get international recognition.

Asked if he were taking a more moderate line than Khomeini, Shariatmadari would only admit that "there might be different tactics to reach the same end." The common goal, he added, "is still an Islamic government."

Shariatmadari said he opposed continued strikes against the Bakhtiar government in such vital sectors as food imports and oil production for domestic needs. "But all other strikes should continue until the establishment of an Islamic government," he said.

Sitting on a Persian carpet next to a kerosene heater in an otherwise bare room, the bespectacled ayatollah said he favored Khomeini's return to Iran from his 15-year exile, indicating he wanted to try to talk the hard-line opposition chief to some sort of compromise now that the shah has left the country.

"Now is the best time for him to come back," Shariatmadari said. "When the shah was in Iran, it was possible he would have been arrested. But now that the shah is no longer here, he should return. If he comes back, it will be possible to consult each other on matters."

An aide to Shariatmadari denied there was any rivalry between the two senior ayatollahs, but he conceded that "recently there has been a certain amount of friction between the followers of Khomeini and Shariatmadari."

Marchers shouted slogans in support of both leaders today during the largest demonstration this city has seen. More than 100,000 people took part, many of them from surrounding villages. Some 6,000 demonstrators reportedly came by bus from Shariatmadari's native Azarbaijan Province in northwestern Iran.