Maersk said it was too early to predict the financial impact of last month's global Petya cyber attack that hit the shipping giant's computers and delayed cargoes.

But the company said that normal operations had resumed at its ports. 

AP Moller-Maersk is the Danish owner of the world's biggest container shipping line.

It operates 76 ports via its APM Terminal division and was one of the many firms hit by the ransomware virus along with Russia's Rosneft and advertising agency WPP. 

For the shipping sector, this was among the biggest-ever disruptions given Maersk handles one out of seven containers shipped globally. 

"Our first priority has not been to look at the financial impact," Robbert van Trooijen, Maersk's Asia Pacific chief executive told reporters on a call. 

"It is too early to predict what the impact will be on the quarter-two, or potentially the quarter-three result," he added. 

The attack did not impact Maersk's physical loading of goods, but disrupted data-reliant processes such as creating arrival notices and obtaining customs clearance - leading to congestion at some of its ports, including in the US, India, Spain and the Netherlands. 

Van Trooijen said all ports Maersk worked with were now back on stream and releasing cargo. 

"Over the last 48 hours we are basically ensuring that just about every port in the world is able to receive and release cargo again." 

He said it was unclear how many bookings had been cancelled due to the attack which spread globally on June 28, but the firm was now seeing a rebound in bookings as systems recovered.

Maersk would discuss settlement and liability issues with individual shippers who had been affected, he added. 

The cyber virus is believed to have first taken hold in Ukraine before spreading globally where it locked machines and demanded victims post a ransom worth $300 in bitcoins or lose their data entirely. 

Van Trooijen said the company did not believe Maersk was deliberately targeted, given the virus' geographic reach, and that it would continue to work with cybersecurity and software firms to ensure it was as protected as it could be. 

He, however, warned it would be difficult to guard against new, random viruses. 

"There was nothing in terms of patches that we missed, there was no cyber security measures that we didn't take, so we were already in quite a strong position," he said.

Yesterday consumer goods maker Reckitt Benckiser said it was downgrading its growth forecast, becoming one of the first companies to quantify the cost of the global cyber attack which disrupted its manufacturing and distribution operations.