Danish shipping giant A.P. Moller-Maersk said it had restored its major applications, as it brings its IT systems back online after being hit by a major cyber attack last week.
"Today we can finally reopen our key applications," Maersk said in a statement.
The company, which handles one in seven containers shipped globally, said it expects to have all its 1500 applications fully functional within a week.
Maersk said on Friday it expected client-facing operations to return to normal by Monday and was resuming container deliveries at its major ports.
Maersk's port operator APM Terminals said on Sunday all terminals had resumed operations and said it would continue to increase productivity and available services. The Maasvlakte II terminal in Rotterdam would be able to make import deliveries starting Monday, it said.
"We can, with great certainty, say that we have never experienced anything like this and therefore we are extremely excited to have achieved a milestone in the journey to be back fully online," Maersk said in the statement.
"We are humbled by the number of people who have offered their help, and the flexibility shown has been tremendous."
Swiss container line MSC (Mediterranean Shipping Company) said on Monday it had worked with its vessel sharing partner Maersk to avoid any serious disruptions.
MSC said several vessels were diverted to other terminals in recent days, adding that shared operations were now running smoothly.
"The biggest challenge facing all carriers was to avoid the APM Terminals which were not in operation," said Gianluigi Di Maio, MSC’s senior vice president of network planning.
"Thankfully, we have a lot of alternative terminals to choose through our subsidiary TIL and other suppliers. Our aim is to minimise any possible disruption by utilising these other terminals."
Maersk and MSC are the world’s top two container shipping lines.