Negotiations on a new IATSE contract went deep into the night on Wednesday, but the two sides were unable to bridge their differences and wrapped without a deal.
More talks are expected to be added to the schedule, possibly as soon as late next week.
The two sides are said to have reached a compromise on several significant issues including, most notably, artificial intelligence. But the talks have yet to produce an agreement on overall wage increases or on how to close a $670 million shortfall in the health and pension plans over the next three years.