* Maersk's container shipper and port units hit by cyber attack
* Maersk Line having to take new orders manually
* Port operations from Mumbai to Los Angeles disrupted (Adds port details)
COPENHAGEN, June 28 (Reuters) - The owner of the world's largest container shipper Maersk Line, said its computer systems were among those hit by the global Petya cyber attack, causing it problems processing orders and delaying cargoes.
Denmark's A.P. Moller-Maersk, which handles one out of seven containers shipped worldwide, could not say when it expects its business to return to normal.
"It will have an impact on vessels or cargo that loaded yesterday, today and maybe also tomorrow," Maersk Line Chief Commercial Officer Vincent Clerc told Reuters on Wednesday.
The cyber extortion, which has disrupted businesses around the globe, has also caused congestion at some of the 76 port terminals run by Maersk's APM Terminals unit, including in the United States, India, Spain and the Netherlands.
Due to limited access to some of its computer systems, Maersk also has problems processing orders taken just before the breakdown, Clerc said.
When the attack began, on Tuesday afternoon in Europe, the company decided to take down a number of systems as a precaution. The company is working on a technical recovery plan, Clerc said.
For now, Maersk is using alternative channels to take orders manually and to communicate with customers, he said.
He said no data had been lost due to the cyber attack, and that the company would be able to resume operations "right away" once the issues were solved.
Paul Tsui, managing director of one of Maersk's clients, Hong Kong-based logistics company Janel Group, said in an email sent to Reuters that "the system of Maersk has been shut down and not able to (be accessed) since late evening yesterday. Therefore, all booking, information submission (..) are affected."
Sydbank analyst Morten Imsgaard said the situation would not be tenable for Maersk "for many days". "It could have a large economic impact for the company, although it depends on how soon it will be able to get its systems running again."
Maersk said operations at some of APM Terminals' 76 port terminals around the world, including Los Angeles, were affected.
A spokeswoman for the Port in Barcelona said one of the two big container terminals run by Maersk was affected. At the Spanish port of Algeciras, operations at one of two terminals run by APM Terminals has been down since Tuesday, a spokeswoman said.
A Maersk-operated terminal at India's largest container port JNPT, near Mumbai, has also been disrupted, the port said on Wednesday.
The Port of New York & New Jersey said in a tweet on Tuesday that APM's Terminal would be closed on Wednesday.
In Aarhus, the biggest container terminal in Maersk's home country Denmark, APM Terminals was using alternative methods of communication when loading and offloading vessels.
"We have found a solution where we work outside the Maersk network," said Steen Davidsen, managing director at the terminal, told Reuters.
"It's not quite so fast, but at least we can operate and customers can be serviced," he said.
Two terminals in Rotterdam, one of Europe's busiest ports, have also been affected, Dutch broadcaster RTV Rijnmond reported on Tuesday. (Reporting by Teis Jensen, additional reporting by Jacob Gronholt-Pedersen, Paul Day, Keith Wallis and Alexander Cornwell; editing by Adrian Croft and Elaine Hardcastle)