The vote was 65,463 to 53,091 in favor of the contract, said Teamsters President William J. McCarthy in a statement from union headquarters in Washington.
The new contract, which covers about 146,000 full- and part-time UPS employees, is retroactive to Aug. 1 and runs through July 31, 1993.
It raises wages for the average full-time driver to nearly $18 an hour by Aug. 1, 1992.
McCarthy said the Teamsters' negotiating committee had recommended the membership reject the pact.
"I am disappointed that the company went to unprecedented lengths to persuade the workers to vote for their offer," he said. "In the final outcome, I believe that many of the company's employees were frightened by management's ability to use permanent replacement workers, or scabs, in the possible event of a strike."
UPS, the world's No. 1 package handler, delivers more than 10 million packages a day, and made 2.8 billion deliveries in 1989 for $12.4 billion in revenue. It has about 150,000 part-time and full-time employees who are Teamsters members, out of a total work force of 230,000.
The strike threat forced UPS customers and competitors to develop alternate plans. Some customers began shifting their business to the U.S. Postal Service or Roadway Package System, Inc. of Pittsburgh, UPS's two main ground-delivery competitors.
The proposed contract raises wages for the average UPS full-time driver a minimum of $1.50 an hour by August 1, 1992, to nearly $18 an hour from $16.10.