“Effective immediately, all current job actions will cease and all work covered by the Master Contract will resume,” said a joint statement by the ILA and the employers’ group – United States Maritime Alliance (USMX).
Under the tentative agreement, wages would go up by 62% over the next six years, BBC News understands.
But negotiations will continue over a number of outstanding issues, including automation.
The union had been calling for a 77% wage hike, while USMX had previously increased its pay rise offer to almost 50%.
The BBC has contacted the ILA and USMX for comment.
“The short ILA strike… will surely be ranked as one of the most lucrative 3 days in labour-management history,” said Patrick L Anderson, CEO of business consultancy Anderson Economic Group.
“The ILA workers have apparently gained 60% wage increases after giving up 3 days of work in a strike that inflicted no serious damage on the US economy.”
The strike started on Tuesday after negotiations failed to produce a new six-year contract.
The walkout was the ILA’s first major stoppage since 1977.
The affected ports included some of the nation’s busiest, including in New York, Georgia and Texas. They are estimated by experts to handle more than a third of US imports and exports.
US President Joe Biden applauded the tentative agreement in a statement on Thursday evening, saying it “represents critical progress toward a strong contract”.
“I congratulate the dockworkers from the ILA, who deserve a strong contract after sacrificing so much to keep our ports open during the pandemic,” Biden said.
“And I applaud the port operators and carriers who are members of the US Maritime Alliance for working hard and putting a strong offer on the table.”
Biden noted the need for ports to be open to “ensure the availability of critical supplies” for those hit by Hurricane Helene, which has left more than 200 people dead in the US south-east.
The news that the stoppage had been suspended was also welcomed by business owners.
“The decision to end the current strike and allow the East and Gulf coast ports to reopen is good news for the nation’s economy,” said Matthew Shay, president and CEO of the National Retail Federation in a statement.
Businesses had been bracing for the possibility of a prolonged shutdown, which threatened to disrupt global trade and the US economy.
Some firms had been building up supplies as warnings of the strike circulated over the summer.
Many consumers had also been fearful and were stocking up on some supplies, like baby formula and toilet paper.
Under the 2018 contract that expired on Monday, dockworkers earned a base hourly wage of $20-$39, as well as other benefits, including royalties linked to container traffic.
Harold Daggett, head of the ILA, demanded companies agree to boost hourly pay by $5 for each year of the contract.
The union, which has about 47,000 active members according to federal filings, is also seeking protections against automation.
