ROME, JUNE 16 -- With the final votes tabulated in Italy's two-day parliamentary elections, Italian political commentators today agreed that the only clear mandate from the poll was that the country be governed by the same five-party coalition formula that governed Italy for the past four years.

"The voters have given a precise, even peremptory, indication: The five-party coalition that died last spring is again the only possible solution at the beginning of the summer," the Milan daily Corriere della Sera said in a front-page editorial that seemed to reflect the thinking of most other editorial writers.

The paper said Socialist leader Bettino Craxi and Christian Democratic leader Ciriaco de Mita, whose dispute over power-sharing brought the coalition down last March, should heed the political realities expressed by the voters Sunday and Monday and find a way to work together again.

There seemed to be no other acceptable political formulas possible, short of bringing the weakened Communists into government -- a prospect virtually all of Italy's noncommunist parties oppose.

Meanwhile, political parties began today to assemble their hierarchies for electoral post-mortems.

Since the Socialists and Christian Democrats both claimed to be winners, it appeared the going would be tough between Craxi and de Mita. Craxi led the coalition for 3 1/2 years; de Mita pulled the rug out from under him when Craxi would not agree to hand over the prime ministership to a Christian Democrat.

The Socialists polled a party record 14.3 percent of the vote -- up 2.9 percentage points for a gain of 21 seats in the Chamber of Deputies.

The Christian Democrats were confirmed as the largest party with 34.3 percent of the total vote for the Chamber -- 1.4 percentage points and nine seats over their showing in the last elections in 1983.

The final tabulations today by the Ministry of Interior confirmed that the chief loser was the Italian Communist Party. In 1976, it polled a record 34.4 percent of the vote; this time, it had only 26.6 percent of the vote for the Chamber and lost 21 seats.

Before President Francesco Cossiga can begin political consultations with party leaders, the new parliament must meet and choose its leaders. That will not happen until July 2.