The Gaullist and Giscardist parties have launched an effort overcome their bitter mutual recriminations over the defeat of President Valery Giscard d'Estaing with an agreement to negotiate a detailed electoral alliance for the forthcoming legislative elections.

Gaullist leader Jacques Chirac and Giscardist leader Jean Lecanuet, head of the Union for French Democracy, signed the pact last night, apparently under heavy pressure from Giscardist parliamentary deputies fearful of losing their seats.

There has been a largely negative reaction among the Giscardists to the defeated president's communique earlier this week saying that he lost because of "premeditated betrayals," a clear reference to the lukewarm endorsement he had received from Chirac. The bulk of the deputies apparently feared they would be eliminated by the combined action of the Baullists and Socialists if the public backbiting did not cease.

Even the Gaullists seemed to be worried. As Antoine Rufenacht, Gaullist deputy from Normandy, put it: "Giscard wants Chirac's scalp. Chirac wants Giscard's scalp. Us deputies, we want to survive."

The agreement reached last night is a compromise between Chirac's call for a single center-right candidate in each district for the first round of the two-stage election, expected in late June, and Giscard's initial order that the first round should be treated as a "primary" between the two parties.

They now plan to negotiate on a district-by-district basis, with a joint endorsement probably going to the incumbent in most cases.

In the last legislative elections in 1978, the Gaullists won 150 seats and the Giscardists 138 in the 491-member National Assembly.

Meanwhile, a subtle controversy broke out between Socialist President-elect Francois Mitterrand and Giscard. Mitterrand's transition team had said that it would organize a ceremony for the transfer of power on May 24 and that until then, Giscard and his govenment would continue to be responsible for the conduct of affairs. But today, Giscard sent Mitterrand a telegram saying that he was ready to turn over power on May 19 since "the numberous problems you must confront make a long transition period undesirable."

Behind the complex dispute, buttressed by complicated constitutional arguments over the date Giscard's term expires, apparently is an attempt by both sides to shift responsibility to the other for the defense of the French currency since Mitterrand's election on Sunday.

Prime Minister Raymond Barre had given the Socialists assurances that they could count on him to defend the franc loyally. But yesterday he submitted the resignation of his government and was designated by Giscard to conduct current business only. Previous practice under the present constitution has been that the prime minister submits his resignation to the new president when he takes office.

There has been a major run on the franc since Sunday. The Bank of France has had to disburse 10 percent of France's foreign-currency holdings in four days to prevent it from slipping further. The Bank of France has also authorized record interest rates in a jump to 18 percent from 13.5 percent in four days to make it attractive to keep funds in the country.

The stock market panic that broke out on Monday has apparently quieted down, and it has become possible to resume quoting all stocks. The markets is down an average of 14 percent, however.