UPDATE 1-UK files claim to seabed around the Falklands

(Updates with reaction from Argentine foreign minister, paragraph 6)

By Adrian Croft

LONDON, May 11 (Reuters) - Britain lodged a claim to a large swath of South Atlantic seabed around the Falkland Islands on Monday, setting the stage for a battle with Argentina for control of potentially rich oil and gas reserves in the area.

The dispute over mineral rights could further embitter a long-running dispute between Britain and Argentina over sovereignty over the islands, known as the Malvinas in Spanish, which led to war in 1982.

Britain filed its claim to an extensive area of seabed around the Falkland Islands, South Georgia and the South Sandwich Islands to the United Nations Commission on the Limits of the Continental Shelf, British officials said.

The claim covers an area of about 1.2 million sq km (463,300 square miles), according to Lindsay Parson of Britain's National Oceanography Centre, who helped prepare the filing.

Argentina filed its own claim with the U.N. commission last month which encompasses the same area claimed by Britain.

Argentine Foreign Minister Jorge Taiana said in a statement that Britain's move was "unacceptable and inadmissible," vowing his government would formally object to any attempt to extend the "illegal occupation" of Argentine territory.

Under the U.N. Convention of the Law of the Sea, coastal states may explore and exploit the natural resources of their continental shelf for up to 200 nautical miles from shore.