London (AFP) - A sculpture of a strutting horse skeleton was unveiled in London's Trafalgar Square on Thursday -- wearing a London Stock Exchange prices ticker in an allusion to the city's financial power.

Entitled "Gift Horse", the riderless bronze sculpture by 78-year-old German-US artist Hans Haacke, is on display on the fourth plinth in the British capital's central square.

It replaces German artist Katharina Fritsch's huge fibreglass blue cockerel "Hahn/Cock", which has stood on the plinth since July 2013.

An electronic ribbon tied to the horse's left front leg displays a live ticker of FTSE 100 share index prices, "completing the link between power, money and history" in the city, according to London Mayor Boris Johnson's office.

Twice the size of a real horse, the 4.57-metre tall sculpture weighs 1,700 kilograms (3,750 pounds).

It is derived from an etching by English painter George Stubbs (1724-1806), whose works depicted horses in a much more accurate way than had been achieved before.

Johnson unveiled the sculpture, calling it a "startlingly original comment on the relationship between art and commerce".

He said the "undeniably underfed beast, this emaciated quadruped" was not "a symbol of the excessive pursuit of austerity", but stood "for the horse in all its incarnations".

The artwork is a confirmation that "London is the capital, not just of finance, commerce and everything else, but of course the artistic and cultural capital of the world as well".

New York-based Haacke told AFP: "I often work in relation to a given context".

"Architecturally, geographically and socio-politically this was a very rich place to work with," he said.

Trafalgar Square is named after the British naval victory over the French and Spanish fleets at the 1805 Battle of Trafalgar, a key conflict in the Napoleonic Wars.

There are large stone plinths in each corner of the square, three of which bear statues.

The fourth was built in 1841 to hold a statue of king William IV on a horse, but it was never completed due to insufficient funds.

Since 1998 the plinth has been used to showcase temporary pieces of art, and has so far hosted works including a giant ship in a bottle and a huge nude statue of the English artist Alison Lapper, who was born without arms, during her pregnancy.

In 2016, "Gift Horse" will be replaced by British visual artist David Shrigley's 10-metre high bronze thumbs-up gesture, entitled "Really Good".