Statoil ASA (STO) said the gas leak that began at the Kaarstoe natural gas processing plant late on Jan. 8 has stopped. External resources from emergency services have halted, and conditions are normalizing at the plant, the company added.

Reuters reported that after the leak, which began at 2130 GMT Jan. 8, most production at the plant was shut down, and that there had been a partial evacuation of personnel. Statoil had previously told Reuters that all personnel were accounted for and the situation was under control. Statoil is a technical service provider at Kaarstoe.

Gas production capacity in Norway, western Europe's top supplier, was cut by more than 32 million cubic metres (mcm) per day on Jan. 8, gas system operator Gassco said, including a reduction at the Sleipner gas field.

"More than half of production at Kaarstoe was shut due to the leak, but some parts remain producing. It wasn't fully shut," Gassco's spokeswoman Lisbet Kallevik said.

"It remains unclear how long it will take to get back to full production," she added.

"We have a control of the situation at Kaarstoe, but it will take some time to depressurize the plant. I can't tell how long," Knut Rostad, a spokesman for Statoil, said.

Huge flames could be seen coming from the plant's flares as gas was burned to reduce the pressure at the facility, Statoil said.

A skeleton staff of 25 people remained at the plant to manage the incident.

The gas leak occurred at a facility where pipelines delivering gas from offshore fields connect to the plant, but the cause of the incident has not been determined yet, Statoil said.