The commander of Iran's Revolutionary Guards resigned today in what was seen as a serious blow to President Abol Bani-Sadr's efforts to consolidate his authority and limit the influence of the militant Islamic clergy.

Abu Sharif, recently appointed by Bani-Sadr as commander of the elite fighting force, said he was resigning to protest factionalism and divisions in the corps. He did not explain why these divisions caused him to suddenly resign now.

Last week the Interior Ministry criticized Revolutionary Guards protecting the occupied U.S. Embassy for opening fire during street fighting between rival political groups. One person was reported killed and a number of others received gunshot wounds.

However, the abruptness of Abu Sharif's resignation apparently surprised Bani-Sadr, who waited nearly a full day before accepting it. Yesterday the black-bearded commander, who resembles Cuban President Fidel Castro, stood next to Bani-Sadr as units of the 30,000-man Revolutionary Guards paraded past the U.S. Embassy.

An Iranian newspaper reported, meanwhile, that Iran's newly elected parliament is unlikely to consider what to do about the American hostages until mid-September and that the issue eventually may be put to the Iranian people in a referendum.

The newspaper Donyaye Iran reported that a number of legislators interviewed said the parliament will be occupied with routine business until mid-September. The paper said that if the body cannot reach a unanimous decision on the hostage issue, Iranians should vote in a national referendum on whether the hostages should be freed or tried as spies.

In his resignation statement, Abu Sharif said that "exclusivism and sectarianism" had frustrated his aim of setting up a force to aid the world's oppressed and pursue Iran's revolutionary course.

There was speculation that his move could be linked with a conflict between factions within the guards supporting either Bani-Sadr or the clergy-dominated Islamic Republican Party.

Abu Sharif was appointed commander of the guards last month after serving as their head of operations. His real name is Abbas Zamani. He adopted Abu Sharif as an Arabic code-name in the mid-1970s while serving in Lebanon with the Amal guerrilla group, made up of Lebanese Shiite Moslems.