A rescue operation is under way to save an elderly yachtsman whose boat is adrift near a gas platform in the North Sea.

The 82-year-old lone sailor raised the alarm at around 8.50pm on Tuesday when his vessel suffered a mechanical failure in gale force winds, with 22ft waves.

It happened around 95 nautical miles from Lerwick in Shetland and 86 nautical miles from Norway.

The mechanical problem left the yachtsman unable to steer the 25ft Harrier of Down, which began drifting towards a gas platform with 162 people on board.

They also put out a distress call, although the yacht did not collide with the structure.

The standby vessel Vos Prospector, from the Dunbar gas field, contacted Shetland Coastguard after picking up the yachtsman's call for help and a rescue operation was launched.

Vos Prospector tried to attach a tow line to the Harrier of Down but failed because of the weather.

In coordination with the Norwegian coastguard, two helicopters were on standby but the yachtsman did not want to be airlifted from his boat, leaving it abandoned.

A Norwegian coastguard vessel from Bergen is travelling to the scene and will tow the yacht back to the port.

It is thought the yachtsman, who is English, was travelling from Shetland to Bergen when he got into difficulty.