A pipeline that carries 40% of North Sea oil has been forced to shut for the second time in a matter of months.

The Forties Pipeline has been closed following the problem at 10.20am on Wednesday.

INEOS, which bought the pipeline from BP for £200m last year, said a feed control valve closed at its Kinneil facility and automated systems safely shut the main pipeline system down.

A spokesman said: "INEOS FPS confirms that a feed control valve closed at its Kinneil facility at around 10.20am today.

"Automated safety systems operated as expected to safely close the main pipeline system.

"We have now identified the issue that caused this and are hoping to resolve it this evening.

"We then plan to start-up again overnight."

The pipeline was forced to close in December after a hairline crack was found during a routine inspection.

It later reopened in January.