Parts of the production of the Ekofisk field remained closed down on Tuesday morning after a ship ran into a platform Monday night - and operator ConocoPhillips said it was unsure for the moment when one of the platforms would be restarted.

"We haven't set any (restart) timing yet," British wire services Reuters quoted a spokesman from ConocoPHillips as saying on Tuesday.

"We first need to find out the scale of hte damage and figure out how to fix it," he added.

The service vessel Dig Orange vessel apparently lost engine power and ran into the water injection platform on Monday night.

"No one was injured, but there was damage to the vessel," ConocoPhillips spokesman Stig Kvendseth told local Norwegian news.

Ekofisk platform 2/4A has been shut down until further notice.

The extent of the damage is unclear, the company said.

"The oil platform produces 8,000 barrels of oil a day. It is too early to say when production can resume," Kvendseth told local newspaper Stavanger Aftenblad.

ConocoPhillips notified Norway's Petroleum Safety Authority after the incident.