A former top official of the United Automobile Workers union pleaded guilty Friday to conspiring with fellow officials in a scheme that siphoned hundreds of thousands of dollars in members’ dues to support spending on villa rentals, lavish meals, golf clubs and golf outings.

The official, Vance Pearson, a former head of the U.A.W.’s vast Region 5, which has run from Missouri to the West Coast, could face up to five years in prison and $250,000 in fines.

Mr. Pearson was a onetime deputy to the former U.A.W. president Gary Jones, who has not been charged but is portrayed in documents filed by prosecutors as one of the orchestrators of the embezzlement scheme. Mr. Jones resigned as president last year.

Mr. Pearson’s plea also includes new information about Dennis Williams, Mr. Jones’s predecessor as U.A.W. president, who has not been charged but appears in earlier filings as well.