REUTERS/Aude Guerrucci/File PhotoAug 3 (Reuters) - Thousands of UPS workers will start voting on their tentative contract agreement with the delivery giant on Thursday after local leaders of the International Brotherhood of Teamsters endorsed the union's deal earlier this week. The tentative deal covering 340,000 Teamsters-represented workers at United Parcel Service (UPS.N) averted a threatened strike that could have wreaked havoc on the U.S. economy by disrupting about a quarter of the nation's parcel shipments. Leaders from Teamsters locals oversee messaging and "sell" the deal to members, who vote through Aug. 22. The tentative deal would raise it to $21 from the current $16.20. It remains to be seen whether the group can mobilize enough part-timers, who account for about half of UPS workers.

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Persons: Peter Lyngso, Jose Negrete, Negrete, Lyngso, Lisa Baertlein, Susan Heavey Organizations: Parcel Service, Teamsters, REUTERS, International Brotherhood of Teamsters, United Parcel Service, Monday, Leaders, UPS, Reuters, Thomson Locations: U.S, Orange , California, Washington, Chicago, Anaheim , California, Louisville , Kentucky, Los Angeles