Chadian Information Minister Mahamat Soumaila said today that France would be asked to provide jet fighter air cover for government troops during counteroffensives on the Libyan-backed rebels' stronghold in the northern town of Faya Largeau.

Eight French combat jets arrived here yesterday, but a French military spokesman repeated today that the four Jaguars and four Mirage jets were only to be used to protect French troops, most of which are deployed alongside Chadian government forces.

"We asked France to intervene with its air force when we were being bombed at Faya, and this request is still valid," Soumaila said at a press briefing.

Soumaila was referring to heavy bombing and strafing attacks the Libyan Air Force made in the first two weeks of August against government soldiers at Faya Largeau and elsewhere in northern Chad. Faya Largeau fell to rebel forces spearheaded by two Libyan armored columns Aug. 10, and Libya ended the bombing of other government positions in the north Aug. 12.

While the bombing caused French President Francois Mitterrand to send French troops here as "instructors" to Chad's Army of less than 4,000 men, the French Air Force did not intervene against Libya's Soviet-made combat aircraft. Chad has no air force, and there has been no fighting in this war since Libya stopped the bombing.

A western diplomatic source said today that "there have been reports of minor patrols" by antigovernment forces south of Faya Largeau. He was unable to say whether Libyans were involved.

The source said as many as 3,500 regular Libyan Army soldiers are in Faya Largeau and other towns in northern Chad. The number of rebel troops in Faya Largeau is variously estimated between 2,000 and 3,000.

Soumaila asserted that Libya had impressed Chadians and other Africans into its Islamic Legion and had been flying them into Faya Largeau. These men, Soumaila said, are being rounded up in Libya from among the Africans who went to Libya to look for work.

The rebels nominally are led by Chad's ex-president, Goukouni Oueddei, who fled the capital in June 1982, when the current Chadian president, Hissene Habre, attacked it with his desert guerrilla army. Chad is in its 18th year of a civil war involving 11 personal factions and six private armies.

More than 1,000 French paratroops and Foreign Legionnaires were flown into Chad to help Habre's government after Libya directly intervened in the fighting in early August. Zaire also has 2,500 troops here supporting the government.

France and the United States have donated millions of dollars in logistical and weapons supplies to Habre's government since it came under fierce Libyan-supported rebel attack in late June. France, the former colonial power in this region, has been at odds with Libyan leader Col. Muammar Qaddafi over the latter's decade-long effort to bring the weak governments in the area under his control. The U.S. government is concerned that Qaddafi might use a subdued Chad as a springboard to destabilize the Sudanese and Egyptian governments, two close American allies and neighbors to Chad.

Last weekend, a team of U.S. military experts arrived to assess what additional type of military equipment Habre's government can use. The Chadian government has received $10 million of $25 million in promised U.S. armaments.

"There is the possibility of a small increase" in French troops and weapons deliveries to Chad also, the French military spokesman said in answer to questions. Meanwhile, France's 11th Division paratroop Brig. Gen. Jean Poli, the newly appointed commander of the French military operation here, arrived evening.