The dress sword carried by Napoleon Bonaparte when he staged a coup in 1799 and five of his firearms sold at auction for nearly $2.9 million, US auctioneers announced Tuesday.

The lot, which was put up for sale by the Illinois-based Rock Island Auction Company, was sold on December 3 via phone to a buyer who has remained anonymous, company president Kevin Hogan told AFP.

The sword and five ornamented pistols had initially been valued at $1.5 million to $3.5 million.

With the $2.87 million sale, "the buyer of the Napoleon Garniture is taking home a very rare piece of history", Hogan said. "We are pleased to have provided the opportunity for them to acquire such a historic object."

The sword, with its scabbard, was the "crown jewel" of the collection, according to the auctioneers.

The weapon was made by Nicolas-Noel Boutet, who was director of the state arms factory in Versailles.

The sword and five ornamented pistols. Photo: World Today News

After being crowned emperor, Napoleon is believed to have presented the sword to general Jean-Andoche Junot, but the general's wife later was forced to sell it to pay off debts.

It was then recovered by a London museum. A US collector was its last owner, but the man recently died, according to the auction house.

In May, France celebrated the bicentennial of Napoleon's death.

The famed Corsican is one of the most divisive figures in French history, his huge contribution to the creation of the modern state set against his imperialism and warmongering.