Norwegian energy company Statoil reported on oil leak Thursday near the Statfjord oil field in the North Sea, though it's too early to guess on volumes.

The company said sheen was observed during the loading of oil from the Stratfjord onto the Hilda Knutsen tanker. Loading was halted, though operations at the field are proceeding as normal.

"It is also too early to say how much oil has leaked," the company said in a statement.

Statoil said equipment was on hand to address the spill and relevant authorities had been notified.

There was no word on the spill from the nation's Petroleum Safety Authority.

Statoil shut down its Statfjord C rig in January 2014 after emergency systems detected an oil leak.

The 270 members of the Statfjord C crew were evacuated to lifeboats but returned to their living quarters later in the day.

No injuries were reported. Statoil said the weather in the area at the time of the Stratfjord C incident was "harsh."

Statoil said the region is producing an average 80,000 barrels of oil per day.