Italian President Sandro Pertini dissolved the Italian parliament today, opening the way for national elections later this spring in which the major issue will be the role of the Communist Party in governing Italy.

The 82-year-old Socialist president signed the decree dissolving parliament after meeting with the speakers of the Chamber of Deputies and the Senate.

The move came two days after Premier Giulio Andreotti failed to win a vote of confidence for his new, three-party government, and resigned and it ended two months of maneuvering designed more to postpone elections than to form a new government.

Ever since the Communists provoked the present crisis on Jan. 31 by withdrawing their crucial support from the five-party legislative majority supporting a minority government headed by Andreotti, elections appeared unavoidable.

Now, as over the last several years the main dilemma in Italian politics has been provided by the desire of the powerful Communist Party for full membership in a fuling coalition and the opposition to this of the Christian Democrats, who have headed every Italian government in the last 33 years.

After winning huge gains in the last national election, in June 1976, the Communists were able to win an unprecedented formal role in influencing policy from the Christian Democrats, who are currently unable to govern without the Communists' support.

Their inability to weigh heavily enough on government decisions led to rank-and-file discontent and eventually to a decision by the party leadership that they had sold their support too cheaply.

The options now developing among the Communists, whose first national congress in four years is under way in Rome, are either government membership or a return to the pre-1976 policy of "constructive opposition."

The coming election campaign, which is expected to coincide with the June elections for the European Parliament, is likely to be fought primarily on this issue. A few polls made earlier this year indicate that the Communists would lose a few points from their 34.5 percent high of 1976 and that the Christian Democrats would make some gains. But the Communists appear convinced that only a drop below the 30 percent mark would severely damage their current political leverage.