Charges against two top officials of the Italian central bank of involvement in a growing credit scandal have shocked political and financial circles here and created a serious and unprecented conflict between the Italian government and legislature on the one hand and the Italian judiciary on the other.

On March 24, the governor of the prestigious Bank of Italy, Paolo Baffi, and one of the bank's deputy directors, Mario Sarcinelli, were charged in connection with an investigation begun in 1977 into more than a billion dollars of allegedly irregular subsidized-interest loans granted to SIR , Italy's third-largest chemical complex.

The arrest of Sarcinelli and the indictment of the 70-year-old, internationally respected Baffi on charges of complicity and of "actions of private interest while in public office" unleashed a storm of protest from all political groups.

Sarcinelli was freed from jail on provisional liberty last week and has been suspended from his job.

Close to 100 economists, scores of polical leaders, and several cabinet ministers have spoken out in favor of the two officials' competence and honesty. The Interministerial Commission on Credit and Savings issued a statement that approves the comportment of the governor, expresses full confidence in him and in all the other members of the directorate, and urges them to continue their activity.

The entire senior management of the bank had threatened to resign unless Sarcinelli was released from jail immediately.

A similar statement of backing signed by representatives of all of Italy's major parties-including the Communists-came from the parliament. But the only response from the procuratore capo, or district attorney, of Rome has been his insistence that there is a legal basis for the investigation being conducted by two Roman magistrates and that the Italian judiciary will reject all politial pressure and intimidatio

Judicial sources have said the the investigation even may be broadened and that the charges against Baffi could be changed to embezzlement. Meanwhile, another judicial inquiry was being made into those central bank employes who had gone on strike in defense of the two officials.

The charges against Baffi and Sacrinelli relate specifically to allegations that the bank's vigilance committee failed to notify judicial authorities about irregularities found in a central bank inspection of a loan granted to SIR by the Sardinian special credit institute, Crodit Industriale Sardo. The vigilance commission's purpose is to protect the interest of depositors through periodic bank examinations. According to Bank of Italy officials, the CIS inspection-begun in August 1977 and terminated this January-was not turned over to the judiciary because officials and lawyers at the bank saw no evidence of criminal action.

The procedures worked out by the bank in recent years are based on preogative spelled out in an article of Italy's banking law, which now appears to be in conflict with a provision of the Italian penal code obligating public officials to report all irregularities to judicial authorities.

Officials of SIR and of several special credit institutes have been under investigation for improper use of low-interest-rate loans for 18 months.

But recent revents are likely to hinder a proposed rescue operation for the giant Sardinian-based conglomerate, described as on the verge of collapse.