The new agreement averted a strike that would have begun if Yellow had remained delinquent on payments to a fund that provides benefits for most of the company's workers.
UPS said that it is pleased to be continuing contract negotiations and that it's prepared to meet some of the union’s demands for better pay and more benefits.
Millions of Americans have grown accustomed to next-day and same-day delivery of their goods. But that level of service might not be sustainable for much longer.
The union said that a board overseeing the Teamsters' pension and welfare funds will suspend benefits starting July 23 unless Yellow Corp. makes the payments it missed July 15.
The deal will help ease pressure on United, which has come under criticism after a series of delays and cancellations to flights, even as it experiences soaring demand.