(Reuters) - A union representing dockworkers on the U.S. East Coast has reached a labor agreement with shippers that will avert a strike that threatened to wreak havoc on the U.S. economy.

The International Longshoremen's Association (ILA), which represents 14,500 workers at 15 container ports in the eastern United States, and the U.S. Maritime Alliance (USMX) of shippers, terminal operators and port authorities, have agreed to extend their current contract by 30 days to finalize details, the Federal Mediation and Conciliation Service said on Friday.

(Reporting By Ernest Scheyder; Editing by Chizu Nomiyama)