Argentine President Leopoldo Galtieri, humiliated by Argentina's military defeat on the Falkand Islands, today was forced out of his positions as president and army commander-in-chief.

Sources said Argentina's armed forces remained divided over Galtieri's replacement as president and the course of the future government.

Galtieri was forced to step down as commander after the top generals reported to him during a lengthy meeting that the Army did not support a continuation of military action against Britain in the South Atlantic, as Galtieri had proposed, the sources said.

"I am leaving because the Army did not give me the political support to continue as commander and president of the nation," Galtieri said tonight as he left the presidential palace. He bitterly added, "I am not one of those who abandons ship in the middle of the storms, with the difficult hours such as those that the nation is living through."

The new Army commander was announced to be Gen. Cristino Nicolaides, a close ally of Galtieri who has been commander of the Army corps based in Buenos Aires. Nicolaides was described by Argentine sources as a tough, aggressive general who has openly battled with civilian leaders in the past and is unlikely to favor a quick return to democratic government.

The commander of the Army, which is the paramount service, traditionally is the most powerful figure in any military government.

Political sources said tonight that Nicolaides' appointment was likely to lead to strong conflicts between military and civilian leaders unless the armed forces offered assurances that they would soon withdraw from power. He also takes up Galtieri's position on the ruling three-man junta of service commanders.

Civilian leaders called tonight for the establishment of a transitional government that would lead directly to democratic elections. "The country does not deserve this sad spectacle of the fighting for power in the armed forces," a Radical Party leader, Luis Leon, said after Galtieri's removal was announced.

Buenos Aires was filled with a sense of crisis tonight as rumors swept the city of the struggles within the military and of the future government. But streets remained quiet into the early evening.

Reports said Galtieri would be replaced as president by Gen. Alfredo Saint Jean, Galtieri's interior minister, in an interim solution that would follow established procedures of presidential succession.

There was no official announcement, however, and reports said armed forces leaders were debating various proposals for reorganizing the six-year-old military government, including establishment of a presidency that would rotate among military leaders or the designation of a civilian as chief executive.

The position of Navy Commander-in-Chief Jorge Anaya, the chief proponent of Argentina's invasion of the Falkland Islands along with Galtieri, remained uncertain. Anaya, who met last night with leading admirals, issued a statement tonight that made no mention of a possible resignation. The third member of the ruling junta, Air Force Commander Basilio Lami Dozo, was expected to remain in his position at least temporarily.

One widespread report said Anaya would soon be replaced and that the military would name Lami Dozo as the country's president. Sources stressed tonight, however, that high military leaders remain divided and that the political situation was chaotic.

According to Argentine media representatives, the military government imposed prior censorship on all written and broadcast material by Argentine media at 4 p.m. today.

Galtieri, who took office as president last December, formally offered his resignation to a meeting of the Army's 10 top generals early this morning, reports here said.

The Army officially announced this afternoon that the 55-year-old general's request to pass into retirement had been accepted. Nicolaides is scheduled to be sworn in Friday morning in Buenos Aires.

Sources said that the tall, white-haired president had hastened his downfall during a desperate effort to preserve his position this week by promoting a rally in front of the presidential palace that resulted in pitched battles between police and angry demonstrators calling for Galtieri's ouster.

A nationwide television speech delivered by Galtieri Tuesday night was also considered unacceptable by military leaders because it failed to explain Argentina's surrender on the Falklands or establish a clear course of action.

In recent days, Galtieri has been described by press reports and sources as increasingly desperate and emotional. In meeting with Army leaders, he proposed a "total war" with Britain and refused to accept responsibility for Argentina's military defeat. Reports said Galtieri had also attempted to disassociate himself from the decision by Argentine forces to surrender to Britain and had threatened to Army leaders that he would disavow the surrender agreement signed by his commander in the Falklands, Gen. Mario Benjamin Menendez.

Galtieri was reported today to have met with Army leaders until 4 a.m., then returned to the presidential palace for meetings with his closest advisers. Early this morning, Galtieri returned to his home at the military base of Campo de Mayo outside of Buenos Aires before returning to the presidential palace tonight after his resignation had been announced.

At the presidential palace, Galtieri was reported to be meeting tonight with Anaya, Foreign Minister Nicanor Costa Mendez and other members of his Cabinet.

Argentina's military leadership was now expected to announce its acceptance of Britain's call for an end to hostilities in the South Atlantic, sources here said. But the sources said the government remained virtually paralyzed and that no immediate action could be expected, even though Argentina's soldiers, captured by the British, remain without a clear understanding on the means of returning home. Britain has announced its intention of returning the prisoners on receipt of assurances.

The Foreign Ministry did announce tonight that the transfer of Argentine troops from the Falklands to the Argentine mainland was expected to begin early Friday morning. In a communique, the ministry said that "if there were not inconveniences," Argentine and British ships, with the collaboration of the International Red Cross, would begin to transport the troops to the Argentine coast.

A military communique issued today said that Argentine wounded were being evacuated from the Falklands on three hospital boats. The communique added that a total of 549 wounded soldiers had been evacuated from the islands to hospitals on the Argentine mainland since the beginning of the conflict.

The focus of the continuing political struggles in the armed forces appeared to be over the form of choosing a president and who would compose the new military junta, which until now has been made up by the commanders in chief of the three armed forces.

Political analysts said it appeared likely that Anaya, the Navy commander, would be forced out of the junta within the coming week. Anaya has been reported here to have been an even stronger proponent of the April 2 Falklands invasion than Galtieri and the member of the junta least willing to compromise Argentina's demands of sovereignty over the islands for a diplomatic settlement with Britain.

Air Force Commander Lami Dozo was expected to meet Friday with the leading officers of his service. Political sources said Lami Dozo was easily the strongest among high military leaders because of his moderate position through the conflict and the Air Force's successes in battle against the British task force.

The process that led to Galtieri's forced resignation began Tuesday, when the top Army commanders met to hear his report on Argentina's surrender on the Falklands and his proposals for future action. Galtieri ordered the division generals to consult Army officers before determining their position on whether Argentina should proceed to fight Britain militarily or seek peaceful negotiation on its claim to the islands, according to sources.

At the same time, Galtieri made his position clear to the generals, declaring that Argentina could not give up fighting.

According to sources, the division generals, after two days of internal meetings of Army officers, reported back to Galtieri last night that Argentina should proceed peacefully. At the same time, a number of the generals reportedly expressed anger over Galtieri's television speech on Tuesday and his efforts to gain popular support, including the calling of Tuesday night's rally at a time when a hostile crowd had already assembled in front of the presidential palace.

By this morning, sources said, Galtieri's resignation was already an accepted fact. But political infighting continued through the day over his successor as Army commander. Sources said the strongest alternative to Nicolaides had been the present chief of staff, Gen. Jose Vaquero. He is reported to have endorsed a moderate position for Argentina's future government and to have been open to the possibility of a transitional government leading quickly to democratic elections.

Nicolaides' appointment as commander-in-chief, however, meant that Vaquero automatically would be forced to retire from the Army under service rules because he outranked Nicolaides in seniority.