PARIS, AUG. 10 -- President Francois Mitterrand today rejected a Chadian appeal for increased French air protection against Libyan bombers retaliating for Chad's sudden push into the Libyan-occupied Aozou strip.

The French leader, in a statement to reporters, sought instead to distance himself from President Hissene Habre's conquest of the town of Aozou, the remote area's main settlement. Mitterrand recalled that France has urged Habre to accept international mediation to settle rival Libyan and Chadian claims to the 43,000 square-mile border area separating the two African countries.

"The action he has just taken in that zone commits only him and his country's forces, a sovereign country and, I repeat, an independent one," Mitterrand said. "As for French military deployment in Chad . . . it remains in conformity with decisions already taken by French authorities, not beyond."

The Defense Ministry denied Libyan assertions that French troops took part in the attack Saturday. Radio Tripoli said the Chadian column made its move on Aozou with help from France and "imperialist forces," an apparent reference to the United States.

Both countries, but chiefly France, have offered extensive help to Habre's Chadian National Armed Forces in his campaign to drive Libyan troops from the country. Chadian forces defeated Libyans at the key Ouadi Doum base March 22 and cemented their control of northern Chad with the conquest of the Faya Largeau oasis five days later, routing Libyan defenders.

Habre vowed then that he also would recapture the Aozou strip, which has been occupied by Libya since 1973.

Prime Minister Jacques Chirac's government provided substantial logistical and other support in the earlier fighting, stationing a French force in Chad that this spring reached more than 2,000 men backed by a number of Jaguar warplanes. But French air protection generally has been limited to Chad's southern half below the 16th Parallel, meaning that Habre could not count on French planes for his attack into the far northern Aozou strip.

Mitterrand said the French position was made clear to Habre during the Chadian leader's visit to Paris last month.

But the Chadian ambassador in Paris, Ahmad Alam-Mi, urged over the weekend that French planes offer cover against Libya's retaliatory bombardments "well above the 16th Parallel." This, he said, would "permit us to consolidate what we have accomplished and put an end to Libyan expansionism."

Libyan leader Col. Moammar Gadhafi has claimed the Aozou border strip as Libyan territory on the basis of an accord signed in 1935 by France and Italy, respectively the Chadian and Libyan colonial rulers at the time, and a secret sale he said arranged in 1973 with the then-president of Chad, Francois Tombalbaye.

France has argued that the 1935 accord was never ratified and thus is invalid. French officials have said Gadhafi has never proved the alleged sale by Tombalbaye with any documentary evidence.

In any case, they have said, the dispute should be settled through mediation by disinterested third nations or the International Court of Justice in The Hague.

The Chadian Embassy in Paris reported today that Libyan warplanes continued bombing Chadian positions near the town of Aozou. The Libyan planes also have been attacking positions in the Tibesti mountains inside Chad proper just south of the Aozou area, diplomats here said, as well as the Faya Largeau oasis, according to a Chadian government radio report today.

The communique said more than 400 Libyans and 17 Chadian soldiers died in the battle for Aozou. Libya has installed a major air base at Tanoa on the northern edge of the Aozou strip about 50 miles north of Aozou town. This would be a likely next target if Habre wants to establish his sovereignty throughout the Aozou region, observers here said.

Seeking to demonstrate that it was not part of the attack on Aozou, the French Defense Ministry has refused to confirm or elaborate on Chadian reports about the action.