The interior was designed to give a flexible work space

The site at Paternoster Square, near St Paul's Cathedral, will not have a trading floor but will be used as a centre for meetings and conferences.

Its interior was devised by design firm Gensler with the aim of creating a flexible work space.

At the official opening on Tuesday the Queen switched on "The Source", a commissioned artwork which marks the start and finish of each day's trading.

The artwork will be permanently positioned in the main entrance of the London Stock Exchange's new building at 10 Paternoster Square.

Christopher Gibson-Smith, chairman of the London Stock Exchange, said: "The Queen opened the former Stock Exchange Tower in 1972, and we are delighted that she has returned to open our new headquarters.

"The contrast between the two buildings underlines just how much the London Stock Exchange has changed in the last 30 years."