Italian Premier Giovanni Spadolini today presented his resignation for the second time in three days, saying that a parliamentary debate yesterday and today had confirmed his decision to step down.

President Sandro Pertini announced that consultations for the formation of a new government will begin on Monday. It would be Italy's 43rd government in the 37 years since the end of World War II.

When Spadolini had first sought to resign on Thursday, the 86-year-old head of state had rejected his resignation and directed him to take the question to parliament.

Spadolini did so, declaring in the Chamber of Deputies yesterday that there is "a profound malaise that continues to throw long shadows over our national political life."

The 57-year-old former historian and journalist cited what he termed an unacceptable public dispute that broke out between Italy's Socialist finance minister and its Christian Democratic treasury chief during his absence on an official visit to the United States.

Spadolini, a Republican, said that despite Italy's economic and financial problems, conflicts among the five parties in his coalition had become sharper and attempts to mend the rifts had proven useless.

Since taking office 18 months ago, Spadolini's task has been complicated by sparring between the Christian Democrats and the Socialists. He has spent as much time trying to patch up their quarrels as trying to solve Italy's economic woes.

Both the Christian Democrats and the Socialists said today that they consider the current five-party political coalition formula still valid. But if attempts to form a government fail, Pertini could be forced to dissolve the legislature and call early elections, either now or in the spring.

Pertini is known to prefer that the elections be held in June 1984 as scheduled, and he is expected to make every effort to avoid dissolving the parliament.