Moving fast today to exploit his party's sweeping parliamentary election victory, French President Francois Mitterrand accepted the resignation of Prime Minister Pierre Mauroy and his interim Cabinet and charged Mauroy with forming a regular government that could include some Communist ministers.

Socialist and Communist negotiators huddled all afternoon and met again late into the night in an effort to agree on a mutually acceptable program to which Communist ministers would be willing to pledge their loyalty. The Socialist delegation, whose leader Lionel Jospin had lunched first with Mitterrand at the Elysee Palace, arrived at Communist Party headquarters for the first meeting 45 minutes late, as if to stress who holds the whip hand. f

A second meeting took place late in the evening at Socialist headquarters after the two sides failed to gree earlier on statements about such basic foreign policy questions as the Soviet presence in Afghanistan and the Soviet SS20 missiles aimed at Western Europe, according to well-informed sources. Some observers speculated that the Socialists had set the conditions too high for the Communists, meaning a new Cabinet might be formed without Communists while negotiations continued with a view to bringing them in later.

The Socialist effort to bring the Communists into the governmental tent follows the election of 289 deputies of the Socialist Party and its close allies to the 491-seat National Assembly, a majority of 44 and 2 1/2 times the Socialist representation in the previous lower house of parliament.

The Communists emerged with 44 seats, slightly more than half the previous number. The Gaullists got 83, a drop of 72, and the Giscardists held on to 72 of their previous 133.

"One wonders," editorialized the conservative editer of the newspaper Le Quotidien de Paris, "whether the great victory of Francois Mitterrand is not more his having cut down the Communists than having defeated" incumbent president Valery Giscard d'Estaing.

Mitterrand intimates argue that it is better to neutralize the Communists by bringing them insdie the Cabinet than to let them be free to strike from the outside and restore their political health as an opposition force. Nevertheless, the leading moderates in the Socialist government -- Foreign Minister Cluade Cheysson, Finance Minister Jacques Delors and Interior Minister Gaston Defferre -- are reliably understood to be arguing against Communist participation.

The center-right coalition that backed Giscard appears to be in even more disarray than the Communists after the defeat of 16 out of 26 of the Cabinet led by former prime minister Raymond Barre under Giscard. The remaining 155 Gaullist and Giscardist deputies are split on which of three feuding rivals to recognize as their political leader -- Giscard, Barre or Gaullist leader Jacques Chirac.

"Francois Mitterrand Holds All the Cards" was the banner head on the conservative newspaper Le Figaro, "Mitterrand the Sole Master on Board," headlined the Bordeaux paper Sud Ouest and "The Socialist Party Devours Everything" was the main head on the Quotidien. Combat Socialiste, the victorious party's organ, headlined "Socialism's Hour Has Finally Arrived."

A widespread theme of editorial comment, even among those friendly to the new government, consisted of warnings that the Socialist should do a better job than the Giscard government of avoiding the arrogance of power.

While leading Socialist spokesmen volunteered their recognition of the dangers of absolute power, there seemed to be a great deal of concern about how to maintain discipline over such a large parliamentary group divided into four main factions -- the followers of Mitterrand consisting of slightly more than half; about 50 Mauroy followers: a like number of partisans of Economic Planning Minister Michel Rocard, who had challenged the president for the party nomination; and about 35 members of the organized left wing, known as CERES.

Even though the Socialists outpolled the Communists for the first time in its working-class bastions, the middle-class social base of the Socialist Party was reflected by the makeup of the parliamentary group, which included about 130 teachers and professors, 35 engineers, a large number of civil servants and only one blue-collar worker. The Communist deputies include 12 classified as workers.

Socialist Party membership has ballooned in recent weeks and has passed the 200,000 mark, according to party spokesmen. The Communists claim twice as many members, but this number is believed to have dwindled in the last three years to about the same number of activists as the new Socialist high.

Mitterand's answer to the problem of keeping control of his ideologically diverse following -- stretching from dedicated Marxists in CERES to the equivalent of moderate New Dealers among the Rocardists -- has so far been to place distance between himself and the daily arguments of his ministers, keeping his own thoughts something of a mystery and serving as a distant inspirer.

"He is a kind of de Gaulle of the left," said one Frenchman, referring to the way Charles de Gaulle kept himself aloof and maintained his authority by exercising it relatively sparingly. As long as he did not consider questions fundamental, de Gaulle tolerated a large amount of pulling and hauling among his followers.

Yet Mitterrand's obvious intention to use the powers of the French presidency to the full has inspired a lot of ironic comment among opponents who recall his frequent allegations that de Gaulle abused his powers. In an obvious attempt to avoid the kind of televised campaign appeal for which Mitterrand regularly criticized de Gaulle and his successors, the new president called for the election of a Socialist majority at a large provincial meeting. Then, members of Mitterrand's staff complained to the three state television networks that they did not cover enough of the president's speech and failed to show how large the crowd was.

Late last week, Communications Minister Georges Fillioud, a former radio journalist who once was dismissed for his Socialist affiliations, publicly encouraged state television and radio journalists to defy their bosses appointed by the previous government. He said those bosses were not being asked to go but that they were not being asked to stay either. His words created a major stir in the press. They were apparently designed to open the way for new chiefs immediately pending the time-consuming preparation of a statute of autonomy for the state-owned media.

After the Socialist have pledged that there would be "no witchhunts" in the media, prominent television interviewers and commentators closely identified with the Giscard government have been handling the new rulers with the kind of respect they used to reserve only for the old ones. Finally, today, two of them decided to act on the message that their presence is no longer really desired. Maurice Ulrich, head of Channel 2 and just reappointed by Giscard in November for a second three-year term, and Roland Faure, news editor of Radio France, both resigned.

The respected Faure is the former editor of the conservative newspaper L'Aurore who resigned that post in 1978 after the paper fell under the control of Robert Hersant, a controversial right-wing publisher.