CHARLESTON, S.C. — Debris and an oil slick were spotted in the Atlantic off the South Carolina coast as the search expanded today for an F-16 fighter pilot whose jet collided with another during night training exercises.

"We did have a report of an oil sheen which might be consistent with fuel from the fighter jet itself and we have also had a report of a small amount of debris," said Capt. Michael McAllister, commander of Coast Guard Sector Charleston.

The search was expanded from 750 to 1,300 square miles as Coast Guard and Air Force aircraft joined vessels from the Coast Guard, Navy, law enforcement and commercial shippers searching for Capt. Nicholas Giglio. He is based at Shaw Air Force Base in Sumter.

McAllister, who said he did not know exactly what the debris was, said there would have been a tracking beacon both on the pilot and his ejection seat, but no signal has been picked up.

"We presume there is a pilot who is in the water and needs to be rescued," he said. "The lack of a beacon might indicate that the pilot didn't safety eject or that there was an equipment malfunction. It makes it more difficult for us since we don't have the beacon to hone in on."

The planes collided Thursday around 8:30 p.m. about 40 miles off the South Carolina coast.