LONDON (AP) _ In a remarkably fierce bidding battle, a rare 19th century German mechanical calculator was sold on Wednesday at Christie's auction house for nearly $12 million - about 385 times more than expected.

Edgar Mannheimer, a Swiss collector, won the cylindrical gilt-and-brass device with a telephone bid after competing with a bidder in the saleroom.

The atmosphere in the auction room was so tense during the bidding that when the final gavel fell, applause broke out.

The price, including Christie's fee, was 7,701,500 pounds ($11,860,300).

''In 20 years at Christie's it's the most astonishing sale I've ever been to,'' said auctioneer Dominic Chichester. ''When we got to a million pounds I thought 'this really must be it. This must be an end.' Then 2 million, 3 million...''

Christie's had set an estimate of 15,000 to 20,000 pounds ($23,00 to $31,000) for the calculator, which is 8 1/2 inches in diameter and 3 inches long.

It was made in 1822 by Johann Christoph Schuster, a maker of instruments and clocks who worked in Ansbach, Germany in the late 18th and early 19th centuries.

Similar instruments were in museum collections in Germany, but none were recorded in private collections and so had not appeared on the market, a Christie's spokesman said.

No details were available about the private seller of the calculator, Christie's said, but Independent Television News said he was asleep when the auctioneers called to tell him how much he had made. There was no further information about the buyer.