IT was among the more bizarre occasions even for a monarch of 52 years standing.

The Queen placed her gloved hand on an electronic ball and 729 spheres, suspended on metal cables, began to levitate.

A quizzical Duke of Edinburgh looked on as the white globes rose into the air and formed seemingly random patterns the height of London's new Stock Exchange building.

The modern sculpture, entitled The Source, stood in stark contrast to the neighbouring classicism of Sir Christopher Wren's St Paul's Cathedral.

But much depends on the movement of the spheres for, at the end of each day's trading, they will indicate the state of the London market - up or down.

Just as a famous bell is rung to commence and cease trading on New York's Wall Street, in London there are now the moving balls.

The Source, permanently positioned in the main entrance atrium of the relocated Stock Exchange headquarters in Paternoster Square, in the City of London, was designed by artists Greyworld.

Controlled electronically, each sphere is meant to move independently, forming random shifting patterns or words, numbers and shapes fed in directly from the world's media.

The kinetic sculpture will mark the start and finish of each day's trading, showing with an arrow whether the market has closed up or down, and giving the opening or closing price of the FTSE 100 Index.

Each sphere is lit from within and contains 21 separate components.

They are suspended on a total of 5.6 km of metal cable.

The Source is 10m taller than the Angel of the North sculpture at Gateshead.

Yesterday saw the official opening of the building which replaces the Stock Exchange's tower building in Old Broad Street, the site of trading for more than 200 years.