The United States Maritime Alliance said on Wednesday it reached a tentative agreement on a new six-year master contract with the International Longshoremen’s Association.

Dockworkers represented by the International Longshoremen’s Association negotiated to avoid a second port strike in a matter of months.

Automation was at the center of a long-running labor dispute that threatened to close East and Gulf Coast ports.

The union representing 45,000 dock workers on the U.S. East and Gulf Coasts and their employers on Wednesday said they reached a tentative deal on a new six-year contract, averting further strikes that could have snarled supply chains and taken a toll on the U.

An agreement on automation and job preservation was crucial to the six-year agreement between the union and management at major East and Gulf Coast ports.

The United States Maritime Alliance and the International Longshoremen's Association reached a deal on a contract Wednesday night, avoiding a strike that could have closed ports up and down the East Coast and crippled the U.