A copy of the original telex informing the British government of the Argentine military surrender in the Falklands war sold Thursday for £7,500 ($12,000, 9,000 euros), Bonhams auction house said.
A private US buyer bought the message sent by Major-General Jeremy Moore, the commander of the British land forces that retook the islands in the South Atlantic Ocean, at a sale in London.
It had been expected to fetch between £2,000 and £3,000.
The auction took place the day after the 30th anniversary of the Argentine invasion, which was marked by a simple candle-lighting ceremony in Britain and a defiant speech by Argentine President Cristina Kirchner.
There has been heightened political agitation in Argentina over the Falklands in the run-up to the anniversary.
The telex states that the Argentine junta's forces had laid down their arms throughout the archipelago, and the islands were "once more under the government desired by their inhabitants".
General Mario Menendez, the commander of the Argentine garrison in the Falklands capital Stanley, surrendered to Moore on June 14, 1982.
"In Port Stanley at 9 o'clock pm Falkland Islands time tonight the 14 Jun 1982, Major General Menendes (sic) surrendered to me all the Argentine armed forces in East and West Falkland, together with their impedimenta," the telex reads.
"Arrangements are in hand to assemble the men for return to Argentina, to gather in their arms and equipment, and to mark and make safe their munitions.
"The Falkland Islands are once more under the government desired by their inhabitants. God save the Queen. Signed JJ Moore. Msg ends."
The message was sent via special forces to the Government Communications Headquarters in southwest England.
Bonhams said the telex comes from a naval-related source.
"This remarkable document encapsulates perfectly the very moment of total capitulation by Argentina's 12,000-strong occupying forces in the Falklands," auction house chairman Robert Brooks said.
"It is a rare find of great historical importance."