An unprecedented shutdown at Le Monde, the voice of the French establishment for the past four decades, has drawn attention to the growing problems faced by one of the world's great newspapers in keeping pace with the changing views of its readers.

One of the peculiarities of Le Monde, a gray, tabloid-sized paper that long has been required reading for French bureaucrats and opinion-makers, is that it is owned and run by present and past employes. For the staff to go on strike against itself sounds illogical. But this week, for the first time in the newspaper's history, the unthinkable happened.

For two consecutive days, the paper failed to appear on the streets because of a labor protest by office staff angry about proposed salary cuts and other economy measures proposed by their elected management. They even occupied the newspaper offices, in the heart of the Paris business district, before finally agreeing to suspend their strike until Dec. 6 to allow for negotiations.

The immediate causes of the crisis at Le Monde are mounting economic problems and huge debts caused by top-heavy management and declining sales. But underneath, in the opinion of many of the paper's readers, lies a crisis of political and journalistic identity. Ponderous, opinionated and authoritative, Le Monde has changed less rapidly than the world outside on which it seeks to report.

"Le Monde is no longer in step with the spirit of the times," remarked sociologist Michel Crozier. "Up until the mid-'70s, the newspaper was steadily gaining young readers. Students were obliged to read Le Monde out of a kind of conformity. Now young people are turning to Liberation an iconoclastic leftist daily founded in 1973 . This represents the beginning of Le Monde's decline."

Le Monde's daily circulation, which reached a high point of more than 800,000 following the 1968 student strikes, has declined to less than 370,000 today. What was once a healthy, profit-making enterprise is expected to register a loss of about $4 million this year -- after losses of roughly $2 million in 1982 and $3 million last year.

The same period has seen a doubling in the circulation of Liberation, which is developing into Le Monde's principal intellectual rival and now sells nearly 130,000 copies a day. While Le Monde is still identified with the generation that came to power and influence after World War II, Liberation is the product of the cultural and political upheavals that shook France in 1968.

According to sociologist Crozier, the attraction of Le Monde, which traditionally has sided with the left in French politics, has been blunted as a result of the Socialist election victory in May 1981. Le Monde, he explained, has been reluctant to criticize a left-wing government with the same vigor that it used to attack the succession of earlier right-wing administrations.

"From the moment Le Monde felt embarrassed about attacking the government and seemed to give up a bit of its liberty, it ceased to be satisfying to such a wide range of readers," Crozier said.

When a row broke out in France earlier this month over President Francois Mitterrand's decision to meet with Libyan leader Muammar Qaddafi while Libyan troops were still in Chad in violation of a troop withdrawal agreement with France, it was Liberation that led the press attacks against the government. Other Paris newspapers, including Le Monde, seemed to take their cue from stinging commentaries written by Liberation's editor, Serge July, a former Maoist firebrand who is now one of the country's most influential publishers.

In an attempt to update Le Monde's appeal, the paper's director and editor in chief, Andre Laurens, has introduced a series of changes during the past few months, including a cartoon strip and a weekend supplement. Pictures, once banned altogether on the ground that they clashed with the serious tone of the paper and used up space that was better filled with words, have been allowed in the culture and travel sections.

Laurens has also been waging a board-room power struggle against a group of prominent outside shareholders who would like to appoint a "comanager" to assist him in sorting out Le Monde's chaotic finances. His supporters have depicted the move as a threat to the newspaper's independence and its traditions of self-management by journalists.

The editor's own proposals for solving Le Monde's financial problems include the sale of its Paris headquarters on Rue des Italiens and cuts averaging 10 percent in the paper's salaries, which are generally above industry levels. The proposals will be offered next month to a general meeting of Le Monde's journalists, who control 40 percent of the shares.

A meeting this week of administrative staff and printers revealed deep divisions at the paper between those who wanted to force the management to make concessions by carrying on the strike and the majority who felt it was preferable to negotiate. Jeers went up in the newspaper's packed lunchroom when union officials read out a letter from Laurens promising to bring greater "dynamism" to the paper.

The scene was a far cry from the happy experiment in worker self-management envisioned by Le Monde's founder, Hubert Beuve-Mery, who set up the newspaper after France's liberation from Nazi rule as a counterweight to right-wing newspapers tainted with collaboration during the war.