Thousands of Londoners watched as 12 lasers lit the sky and 30 searchlights connected the structure with other city landmarks, while the London Philharmonic Orchestra provided the soundtrack.

The inauguration was officially launched by Prince Andrew, son of Queen Elizabeth II, and Qatari Prime Minister Hamad bin Jassem al-Thani.

The 310-meter (1,016-foot) building is named for its resemblance to a sliver of glass. However, Prince Andrew's brother, Prince Charles - known for his opposition to modern architecture - has lambasted the construction, saying it looks like a giant salt holder.

London Mayor Boris Johnson, however, told the BBC he believed the structure was "a quite astonishing piece of architecture."

Although the Shard takes over from the Capital City Moscow Tower in Russia as the continent's tallest building, its tenure at the top is likely to be short-lived.

Moscow is set to take the record once again at the end of the year as the 332-meter Mercury City building nears completion.

The Shard, so named by its Italian architect Renzo Piano, remains significantly shorter than the tallest building in the world, Dubai's 828-meter Burj Khalifa.

The Qatar National Bank funded the construction of the London building, which is partly owned by the Gulf state.

rc/cmk (AFP, AP, Reuters)