A strike by dockworkers on the U.S. East Coast and Gulf Coast that disrupted much of the nation's ocean shipping this week ended on Thursday, but a key issue driving labor unrest across the continent — the growing use of automation — was unresolved.

Companies view automation as a path to better profit while unions see it as a job-killer. For North American dockworkers battling automation, Europe's port worker contracts may point a way to resolve the issue.

Some 45,000 port workers from the International Longshoremen's Association union late on Thursday ended a three-day strike that had shut ocean shipping from Maine to Texas after reaching a tentative deal on wages.