The 19-year-old driver of a small pickup truck that crashed on a rural road in Anne Arundel County in April, killing 10 other teen-agers, was convicted here today of manslaughter involving a motor vehicle.

Alan B. Cole of Baltimore could face up to 30 years in prison if given the maximum sentence on all 10 counts. The jury of four men and eight women returned its guilty verdict on the 10 manslaughter charges and four traffic violations, including speeding and reckless driving.

But the jury acquitted Cole on the lesser charge of homicide with a motor vehicle while intoxicated.

The defendant showed no emotion as the verdict was read in Frederick County Circuit Court following three hours of deliberation. He later embraced his distraught sister and parents in the courtroom.

Cole and only one passenger, who testified against him at the three-day trial, survived the late night crash, Maryland's worst auto accident in a decade.

His sentencing will await a background report on Cole to be prepared for the judge.

"I don't think he was suprised," said defense attorney Stanley S. Cohen, who rested his case this afternoon without calling a single witness.

Assistant State's Attorney Scott G. Patterson told the jury that Cole's drinking and speeding added up to gross negligence or wanton and malicious disregard for life, the standard required for conviction on the charge of manslaughter involving a motor vehicle. "The verdict reflects that the total cumulative circumstances constituted gross negligence," Patterson said afterward. "I think it's a proper verdict."

Cole's attorney said he would wait until sentencing before considering an appeal.

While the jury was out, Cole waited nervously outside the courthouse.

"By gross negligence, they're saying I meant to kill my 10 friends," he said. "I didn't mean to kill them. If I go to jail, it's not going to bring them back."

Judge Samuel W. Barrick permitted him to remain free on his own recognizance pending sentencing.

The prosecution's star witness, Kenneth Sassaman, 17, who was riding in the bed of the silver Ford Courier pickup truck just behind the driver, testified he lied when he told police that the truck was only going 30 mph and that he had not seen Cole drinking beer or smoking marijuana.

Cohen attacked Sassaman's testimony, reminding the jury that the youth himself had testified that he drank four quarts of beer before climbing in Cole's truck for the ill-fated ride to a favorite hideaway known as The Pond.

"As far as I'm concerned, anyone who's consumed that much alcohol, I'm surprised he could walk, much less give a description of what someone else was doing," the defense attorney said.

Sassaman also testified that Cole had started to speed up and people were yelling at him to slow down as the truck went down Patuxent Road.

The prosecution never established the exact speed the truck was traveling when it went off the road, glanced off two trees and slammed into a third. But Sassaman testified that at one point, all four wheels left the road when the truck hit a bump.

The National Transportation Safety Board issued a report earlier this month, estimating the vehicle was going between 68 and 74 mph, but Judge Barrick threw out a board investigator's testimony.

The prosecution called 14 witnesses, including several police officers, before resting its case yesterday. But defense attorneys declined to call two of Cole's friends, scheduled to testify in his defense, or Cole himself.

Defense lawyer Cohen said the evidence the prosecution had presented failed to prove Cole was drunk. He said he decided against putting his client on the stand because he had been under a tremendous burden and "we weren't certain how he would hold up under the circumstances."

The lawyer conceded before the jury that Cole "might have acted foolishly and negligently, and unfortunately the results were tragic and devastating. But that doesn't add up to gross negligence.

"We were all teen-agers at one time," he said.