Sabotage produced the biggest oil spill in the short history of the trains-Alaska pipeline and forced a daylong shutdown, but oil began flowing again yesterday and tanker shipments to the lower 48 states were not interrupted.

Alaska state troopers said they had no suspects and did not know what kind of exposive had been used when a two-inch hole was blasted in the pipeline Wednesday afternoon.

John Ratterman, Alyeska Pipeline Service Co., said oil flow resumed at 3 p.m. EST, less than 24 hours after the explosion was reported.

There was enough oil in holding tanks in the pipeline port of Valdez that no delays in tanker shipments were anticipated, Ratterman said.

Thousands of barrels of thick crude oil - there was no more specific estimate available - gushed from the hole in the half-inch thick steel pipe. The spilled oil formed pools and sprayed four acres of frozen tundra with a black film before worker could clamp a huge "sleeve" over the jagged gash in the 48-inch diameter pipe.

Environmental officials were unable to assess the damage immediately because the area was covered by three feet of snow. Alyeska said the oil had not reached the Chena River, more than a mile away.

The largest previous spill on the pipeline occurred during last summer's startup, when a worker accidentally drove a truck into a value on the 800-mile line. That spilled fewer than 1,000 barrels.

Three man were charged with attempting to blow up the line last summer, but the explosive device they set didn't even dent the pipe.

Trooper Lt. George Pollitt said the small hole caused by the latest explosion indicates those responsible had "a knowledge of how to do it."

Troopers found a 20-foot length of slow-burning fuse near the site of Wednesday's blast, about six miles east of Fairbanks.

The pipeline, working since last July, had been carrying 740,000 barrels daily. It was shut down shortly after the spill was reported Wednesday afternoon.

By the time workers arrived, vcrude oil "was hitting the ground and bouncing about 20 feet into the air," said Cal Niver, a spokesman for the federal Alaska Pipeline Office.

Tanker trucks were dispatcher to take away the oil that workers siphoned from large pools around the elevated portion of the line. By late Wednesday, nearly 1,000 barrels of spilled oil - clean enough for use - had been taken to the nearby North Pole refinery.