A supply ship struck an oil rig off the coast of Newfoundland Thursday, putting a four-to-five-metre hole in one of the rig's eight columns.

A spokeswoman for Husky Energy, which operated the drilling field, said the damaged column has been sealed.

"That length of a hole makes up about 20 per cent of the column," said Husky's Colleen McConnell. "However, it is in a water-tight compartment that has now been sealed off from the rest of the rig and the rig remains stable."

Husky said there were 15 people on the ship and 90 on the rig. There was no need to move anyone off the rig or supply ship, Maersk Detector, on Thursday night, McConnell said, but the well is being suspended and the rig will be going into port for repairs.

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The rupture occurred at 3:30 p.m. NT at the White Rose oilfield, about 350 kilometres off the coast of Newfoundland. At the time of the accident waves were as high as six metres.

Transocean, the rig owner and operator under contract to Husky, is the same company that operated the Deepwater Horizon rig before it exploded in the Gulf of Mexico last year.

The company's operations off Newfoundland have not been trouble free, either. It had to stop work on the GSF Grand Banks last month after spilling synthetic drilling mud for the second time in two months. Then on Monday, lines that connect to the blowout preventer were found to be damaged.

The ship that struck the oil rig was damaged above its waterline, but was not in danger of sinking.

Once crews assess how long it will take to suspend the well and move off location, Husky will decide whether people need to come off.

A core crew, however, will stay with the rig, Husky said.

The oil company hopes to have a better idea of what will happen next in the next few days. The investigation will determine how the accident happened.