Ankara: Repairs have started in Turkey on the fire-damaged Baku-Tbilisi-Ceyhan (BTC) oil pipeline, but it is not clear when the line will reopen, a source from the Turkish pipeline company Botas said yesterday.

World oil prices rose last week after the blaze, and estimates that it could take up to two weeks to get the pipeline on stream again.

"Digging has begun to assess whether there has been damage to the valve on the pipeline, which is very important in determining when the pipeline will be reopened," said the senior level source at Botas.

The source told Reuters it would take another two days to clarify when the line could reopen.

"We are working to determine the extent of the damage on the line, it is still impossible to say when repairs will be complete," he said.

According to the method chosen for the repair of the pipeline the process could take one or two weeks or even longer, a Botas source told Reuters last week.

The fire was a result of an explosion in eastern Turkey late on Tuesday last week.

Crucial role

The pipeline normally carries Azeri oil which is high quality and commands a premium.

The $4 billion BTC pipeline can pump up to a million barrels per day, the equivalent of more than one per cent of world supply, from fields in the Azeri sector of the Caspian Sea to Ceyhan on the Turkish Mediterranean coast. Britain's BP owns 30.1 per cent of BTC, while Azeri state oil company Socar holds 25 per cent.

Other shareholders include US companies Chevron and ConocoPhillips, Norway's StatoilHydro, Italy's ENI and France's Total.

Kurdish separatists claimed responsibility for the explosion and said they would carry out more attacks on economic targets inside Turkey.

The source from Turkey's pipeline company said it was still too early to determine whether the fire was a result of sabotage.