LONDON (REUTERS) - Exxon Mobil said it shut one of Britain's main underground fuel pipelines following a report that thieves had tapped into the line and taken thousands of litres of fuel.

Hampshire's Daily Echo newspaper reported on its website that police had arrested two men in connection with the theft of more than 30,000 litres of diesel from the pipeline. That would be worth about 41,000 pounds (S$86,200) at pump prices.

Exxon, known as Esso in Britain, said it was assisting Hampshire Police with their enquiries after the discovery of a store of fuel in the Romsey area and that indications suggested the fuel might have come from a nearby Esso pipeline.

Known as the Midline Pipeline, it runs north from Esso's Fawley oil refinery near Southampton to its terminal in Birmingham, located at Erdington in the city's northeast. "Esso is committed to the very highest standards of safety. The pipeline has therefore been closed down, and our specialists are working to check it and, if necessary, effect any repair,"the company said in a statement on Monday.

Theft of oil from pipelines is relatively rare in Britain, although it is a major problem in countries such as Nigeria, where it is estimated to cost the government up to US$1 billion per month.

Esso is making alternative supply arrangements and does not expect its retail customers to be affected by the pipeline closure, a company spokesman said.

The pipeline has a spur to Birmingham Airport, although this is rarely used now as most fuel supplied to the airport goes by road, he said.

Police were guarding the spot in West Wellow, Hampshire, southern England, where the thieves are thought to have tapped into the 14-inch pipeline, the newspaper reported. The fuel is being stored safely, and engineers from the refinery are working to retrieve it, the paper said, citing police.

A similar incident took place recently in Gloucestershire, the newspaper reported.

While oil theft is rare in Britain, the stealing of metals such as copper cable has led to communications and rail network disruptions, costing the domestic economy millions of pounds.