About 100 oil workers are being flown to Shetland following a power cut on the Clair platform this morning.
BP said the Clair, which lies about 46 miles west of Shetland, lost power at about 5.45am.
The platform with 144 workers was not producing at the time.
As a precautionary measure, the company said 105 “non-essential personnel” were being down manned.
BP said it is working to resolve the issue.