Michael J. Alvino, president of the drivers union, said, "The result of this is that 500 families will be eating again."

The drivers union is considered the only one of the city's newspaper unions capable of halting newspaper operations.

Michael Diana, the business agent for the drivers union, said he would in effect have two categories.

"If they want the paper bad enough, they'll be back," said Frank Sparacino, president of the drivers union.

For the leadership of the drivers union, the November arbitration ruling made a negotiated settlement with The Times much more appealing.

For more than three weeks, the drivers union and transit officials have wrangled about wages, work rules and overtime.

The drivers union then walked out, and the other unions struck in sympathy.

If that occurs and Imperial fails to reach an agreement with the drivers union, the union could lose all of those roughly 550 jobs.

On Monday, the head of Greyhound's drivers union suggested the company's refusal to negotiate is partly to blame for the violence.

Mr. Alvino, who has been president of the drivers union for 16 months, has a reputation for outspokenness.