Government troops yesterday recaptured eastern Chad's largest city and battled Libyan-backed rebels on the highway north of the city, the official radio announced.

The ancient city of Abeche, 100 miles west of the border with Sudan, reportedly was under government control again a day after President Hissene Habre's forces were reported to have been routed from the city by the Libyan-equipped rebels led by former president Goukouni Oueddei, according to United Press International.

"Chad government forces retook the city of Abeche Sunday at noon," said a communique read on state-run Radio Chad.

There was no immediate comment from the rebels, who claimed to have captured the city Saturday.

Abeche, a city of about 25,000 people, lies 434 miles east of the capital of Ndjamena and commands its main road link to Sudan, which backs Habre's government in the former French colony in central Africa.

"Fighting continues north of Abeche on the road linking this city to Oum Chalouba," the radio said, referring to a hamlet 150 miles north on a crossroads leading to the key northern towns of Fada and Faya-Largeau.

Chadian officials never admitted losing the city. One official said the counterattack "began after preparation. Government forces are progressing normally."

The Chadian government has complained that Libyan troops are aiding the rebels in their drive, but diplomats said they have no evidence of Libyan troop involvement. The Libyans, however, are believed to have provided logistical support and arms to the rebels, diplomats said.

The government has received about 200 tons of arms from France since the latest fighting began, diplomats said. Zaire has also sent in about 250 paratroopers to aid Habre's forces.