The State Department confirmed yesterday that the United States is withdrawing its Airborne Warning and Control System (AWACS) radar planes and F15 fighter jets from Sudan because "for the immediate future" they are not needed to monitor fighting in neighboring Chad.

The administration said that the AWACS planes could return to the region on short notice, and that the United States will continue to help government troops battling Libyans and Libyan-backed insurgents in northern Chad. A five-man U.S. military team remains in Chad assessing what further U.S. military aid may be appropriate, Pentagon officials said.

At the same time, the administration raised the prospect of a military stalemate in Chad between the government in the south, supported by France and the United States, and insurgents and Libyans in the north.

An administration official said the Libyans "are at the end of their supply line," and State Department spokesman Alan Romberg said the United States "does not want to see a resolution of the conflict resulting in a partition of Chad."

The sophisticated radar surveillance planes were sent to Sudan, Chad's eastern neighbor, on Aug. 7 to help counter what administration officials called a Libyan invasion of Chad from the north. The planes were intended to help coordinate French military activities supporting the Chadian government, but French officials said they had not asked for the AWACS planes.

The AWACS were never used in operations and, along with eight F15 fighters protecting them and two KC10 tanker planes for refueling, flew only once, in what the Pentagon called a training mission. Reagan administration officials maintained yesterday that the AWACS planes had achieved their purpose.

"The Libyan march southward has been stopped," an administration official aboard Air Force One said yesterday as President Reagan traveled from Los Angeles to Seattle. "The legitimate government of Chadian President Hissene Habre has been preserved. The French have responded in substantial force there."

Asked how the AWACS force accomplished its goals without flying any missions, the official replied, "It just did it."

Habre took office 13 months ago by overthrowing president Goukouni Oueddei. Now Goukouni is attempting to regain power with Libyan backing, which administration officials say would further the expansionist ambitions of Libyan leader Col. Muammar Qaddafi. Reagan said on Aug. 11 that Chad lay within the French "sphere of influence" and, ruling out direct U.S. military intervention, urged France to aid Chad. French officials responded with irritation, saying that they had not requested the AWACS planes--which U.S. officials denied--and that they did not regard Qaddafi as an enemy.

Nonetheless, France has been sending troops, fighter jets and other equipment to Chad in recent days, and U.S. officials say they believe the French presence has halted the insurgent advance.

"We are encouraged by the French deployment of substantial forces to Chad," Romberg said yesterday. "The United States again condemns Libya's blatant act of aggression and affront to international order and calls upon Libya to withdraw."

The withdrawal of the AWACS planes, their accompanying jets and more than 600 support personnel began yesterday and will be complete in two to three days, Pentagon officials said. Cargo jets made 22 trips from the United States to bring support equipment to Sudan, and a similar effort will be mounted for the return, they said. Pentagon officials were unable to provide cost of the mission.