A view of a superconducting solenoid magnet at the European Organization for Nuclear Research (CERN) near Geneva. Major budget cuts at the world's biggest atom smasher over the next five years are set to slow down its quest to unlock the deepest secrets of the universe, management and staff warned.

European budget cuts at the world's biggest atom smasher are set to slow down its quest to unlock the deepest secrets of the universe, management and staff warned on Wednesday.

Member states on the finance committee of the European Organisation for Nuclear Research (CERN) accepted a revised budget proposal with 343 million Swiss francs (331 million dollars, 261 million euros) in savings for 2011-2015, agency spokesman James Gillies told AFP.

The savings represent about 6.9 percent from the original budget request by CERN Director General Rolf Heuer of about 5.0 billion francs for the period that was rejected in June.

Gillies said earlier that budget cuts "will have an impact on the speed to which we get results, but not a dramatic one."

Another 135 million francs in the new 2011-2015 budget will also be set aside to reduce the organisation's debt, he explained after the extraordinary meeting.

CERN said it was trying to avoid harming the huge Large Hadron Collider experiment, a 27-kilometre (16.8-mile) circular particle accelerator buried under the French-Swiss border, and prevent staff cuts.

"The Director General is extremely pleased with the result given the economic climate," said Gillies.

Wednesday's recommendation will now be submitted for a decision by the 20 European nations on CERN's council on September 16.

The head of CERN's staff association, Gianni Deroma, raised the spectre of even deeper cuts that might affect reliability and lead to a repeat of the embarrassing and costly 14-month breakdown shortly after the LHC was started up in 2008.

He told a protest rally by several hundred CERN staff and researchers during the meeting that more cuts could "increase the risk of a breakdown" just as the experiment was entering a period of steady high power operation.

The staff association believes some countries want even deeper savings, including job cuts.

"Budgetary cuts are going to slow down our accelerators," said Deroma.

"Additional budget restrictions could ruin all the efforts made so far and the marvellous first results given by the LHC," he told the rally, where physicists rubbed shoulders with translators and support staff.

The 3.9-billion-euro (5.2-billion-dollar) machine is attempting to recreate powerful but microscopic bursts of energy that mimic conditions close to the Big Bang that created the universe.

After a shaky start, experiments at the LHC have in a few months replicated discoveries that took decades to complete at the rival Tevatron accelerator in the United States.

Scientists say the LHC is constantly setting new milestones with the amount of data collected from colliding beams of particles fired at close to the speed of light.

The LHC is due to be shut down for several months in 2012-2013, after completing its current series of experiments, for an upgrade to delve deeper into the frontiers of science at full power.

Gillies said management was considering whether to save money by shutting down the whole accelerator complex on the Franco-Swiss border during that period, while another experiment due in 2015 might be put off for a year.

CERN said its permanent staff numbers had already been pared down from about 3,000 when development of the LHC began in the mid-1990s to some 2,200 today.

Deroma told AFP: "With 2,250 permanent staff we have trouble honouring all the missions we are given; we can't go any further, that would be catastrophic for CERN."

Staff representatives from several other European science establishments turned up at the rally.

"We share your concerns and are facing similar, though as yet unquantified, measures on Europe's space budgets," said Bruno Leone, a representative for staff at the European Space Agency (ESA).

Scientists are also annoyed that European research budgets did not receive a promised boost during last decade's economic boom.