Retailers can breath a sigh of relief — there won’t be an East Coast port strike this fall.

The U.S. Maritime Alliance and International Longshoremen’s Association on Thursday agreed to extend their collective bargaining agreement covering East and Gulf Coast port workers that was due to expire on Sept. 30 for a 90-day period through Dec. 29.

The USMX, representing container carrier members and every major marine terminal operator and port association on the East and Gulf Coasts, and the ILA, representing 15,000 members working at Atlantic and Gulf Coast ports from Maine to Texas, said they were taking this step “for the good of the country” to avoid any interruption in interstate commerce. The two sides have been in contract talks since March. In 2011, the 14 ports handled more than 110 million tons of import and export cargo.

George H. Cohen, director of Federal Mediation and Conciliation Service, which was brought in to mediate the contract negotiations, said, “The extension will provide the parties an opportunity to focus on the outstanding core issues in a deliberate manner apart from the pressure of an immediate deadline.”

“The 90-day extension is welcomed news for retailers, because it ensures that a work stoppage at the ports will not interfere with the flow of goods during the critical holiday season,” said Kelly Kolb, vice president for government affairs at the Retail Industry Leaders Association. “Ports play a critical role in the supply chain, and a potential disruption would be harmful to the retail industry as it would lead to lost sales and aggravated customers.”

Jonathan Gold, vice president for supply chain and customs policy at the National Retail Federation, said the news “signals that both sides…are serious about reaching a deal,” while providing “for a stable holiday shipping and shopping season over the next few months.”

Gold said the NRF continues to urge management and labor to continue their negotiations until they “hammer out a final contract.”

On the West Coast, the Office Clerical Unit of International Longshore and Warehouse Union Local 63 and the Los Angeles-Long Beach Harbor Employers Association said earlier this month they would continue negotiating throughout the month of September. They are scheduled to update the status of their talks next week.