PARIS, May 5— France agreed today to open its archives to shed light on a dark chapter in French-Algerian relations: the deaths of dozens and perhaps hundreds of Algerians during a 1961 Paris protest march.
Prime Minister Lionel Jospin's office announced that historians would be allowed to sift through the archives to help sort out charges that the police may have been behind the deaths.
Long-unanswered questions about the Oct. 17, 1961, march and its death toll resurfaced last year during the war crimes trial of the convicted Nazi collaborator Maurice Papon, who was the Paris police chief when the protest took place.
Mr. Papon, who was sentenced to 10 years in jail for helping deport Jews to Nazi death camps, admitted at his trial that the bodies of about 30 Algerians had been recovered from the Seine after the demonstration.
But he insisted that they had been killed in fighting between rival Algerian nationalist groups.
Mr. Papon, now 88, later sued historian Jean-Luc Einaudi after he wrote that 200 to 300 Algerians had been killed by out-of-control police officers during the march and that Mr. Papon had covered it up.
Authorities at the time said six people had died. An official report last year suggested that several dozen had been killed.
A Paris court dismissed Mr. Papon's lawsuit, concluding the death toll had been ''significantly greater'' than the official figure.
Two competing Algerian groups -- the National Liberation Front, which ultimately took power in Algiers, and the Algerian National Movement -- frequently killed rivals in Paris as part of the pre-independence power struggle.
Several thousand people were killed this way in France during the Algerian war of independence against France between 1954 and 1962.
But Mr. Papon is alone in ascribing the October 1961 deaths to fighting between Algerian nationalists. Most historians say they occurred when the police vented their anger on protesters for a National Liberation Front campaign of randomly killing Paris police officers.