The 300 million euro ($308.4 million) loan from the European Investment Bank, the EU's long-term funding arm, brings total funding for the project to about three billion euros, mostly from the 20 governments which are members of CERN.

The LHC will smash protons or other particles together and allow scientists to watch the results at a resolution of about one million billionth of a metre, which they hope will give answers to some fundamental questions about matter.

The LHC uses magnets to produce an electric field which accelerates the particles. A big machine means a stronger electric field and faster particles, which pick up speed as they whiz around the ring.

"The main purpose is to recreate the environment which was present in the universe at the big bang moment," said a spokesman for European Research Commissioner Philippe Busquin.

The LHC will allow scientists to tackle mind-boggling questions such as why sub-atomic particles have mass and why are some heavier than others.

CERN scientists say the spin-offs from their research into particles using the LHC could include lasers for precision surgery, making nuclear waste safe, the development of high performance computer networks and cancer research.

Construction of the LHC is due to finish in 2007.