WASHINGTON (AP) -- Dockworkers on the U.S. East and Gulf coasts overwhelmingly approved a six-year contract Tuesday, averting the threat of a strike that could have crippled the economy.

The yes vote was expected after the leadership of the International Longshoremen's Association union reached a tentative contract agreement in January with the U.S. Maritime Alliance of ports and shipping companies.

The alliance approved the contract last month, and on Tuesday rank-and-file members voted for it with nearly 99 percent in favor, the union said in a statement.

The contract calls for a 62% pay hike over six years that would lift hourly wages at the top of the union pay scale from $39 an hour to $63 an hour.

ILA President Harold Daggett, who served as the union's chief negotiator, was quoted in the statement as saying the agreement is "the 'gold standard' for dockworker unions globally."

He remarked that it was a difficult contract to negotiate and even required a three-day strike last fall, but "We now have labor peace for the next six years."

The union and the alliance also reached a truce on the most contentious labor issue on America's docks: automation. The union worries that machines -- especially semi-automated cranes -- will replace human workers. Port operators and shipping companies argue that U.S. ports are falling behind more automated ones such as those in Rotterdam, Dubai and Singapore.

The new contract gives ports more leeway to introduce modernizing technology. But they have to hire new workers when they do, and full automation is off the table.

"The pending contract opens the door a little more for advanced technology and automation," Brian Lynch, leader of the transportation sector at the consulting firm EY Americas, said before the vote. "The door's cracked a bit."

The union went on the three-day strike in October but suspended it to allow for more talks. A prolonged shutdown at 14 ports stretching from Boston to Houston could have delayed shipments to American factories and retailers and driven up costs.

The two sides are expected to meet the week of March 10 to sign the agreement, after which it would go into effect.

Before his inauguration, President Donald Trump voiced support for the union. Claiming to "know just about everything there is to know" about automation, Trump wrote on social media, "The amount of money saved is nowhere near the distress, hurt, and harm it causes for American Workers, in this case, our Longshoremen."