By Andrew Osborn and William James

LONDON (Reuters) - Britain on Monday accused Argentina of a politically motivated and illegal attack on the nascent oil industry around the disputed Falkland Islands, after Buenos Aires said it would seek to seize the assets of drillers operating in region.

On Saturday, a federal judge in Tierra del Fuego ordered the seizure of $156 million (£99.17 million) in bank accounts, boats and other property belonging to six European and U.S. oil companies operating in the islands.

Argentine Foreign Minister Hector Timerman was quoted in the local press on Sunday as saying his country intended to pursue the case as part of its claim to the islands' sovereignty.

Britain, which counts the islands as one of its overseas territories, rejects any such Argentine claims.

"This politically motivated decision to target company assets is a wholly unacceptable attempt to exercise extra-territorial jurisdiction, and has no legal justification whatsoever," said British foreign office minister Hugo Swire.

He said Argentina was conducting a "flagrant and unacceptable campaign to strangle the Falkland Islands hydrocarbons industry."

"This action, aimed at British and international oil and gas companies, has dangerous implications for global business."

The companies named in the judge's order were Premier Oil Plc , Falkland Oil and Gas Ltd , Rockhopper Exploration Plc , Noble Energy Inc and Edison International Spa . They declined to comment.

Argentina claims sovereignty over the South Atlantic islands which it calls the Malvinas, located about 435 miles (700 km) off the coast of Tierra del Fuego. They are inhabited by around 3,000 people, the overwhelming majority of whom say they wish to remain living in a British overseas territory.

Britain and Argentina fought a short war over the disputed archipelago in 1982, after the then Argentine military dictatorship seized the islands by force, and tensions have flared again in recent years with the discovery of oil deposits.

Argentina has promised to resolve the dispute through diplomacy. But the country faces elections in October ahead of which politicians often ramp up rhetoric.

(Additional reporting by Karolin Schaps in London and by Maximiliano Rizzi in Buenos Aires and Rosalba O'Brien in Chile; Editing by Andrew Heavens and Chris Reese)