Ireland's "great" 12.5 per cent corporation tax regime has proven that lower tax rates can increase tax revenue and boost economic growth, according to Larry Ellison, the founder, chairman and chief executive of software company Oracle.

However, Mr Ellison was critical of the Government for imposing restrictions or caps on visas for qualified individuals in any sector in which their skills are in short supply, such as the technology industry.

Speaking to journalists in Valencia, where he is currently based with his America's Cup Oracle/BMW sailing team, Mr Ellison blasted recent European Union proposals for enforced tax harmonisation across EU countries.

Standardised taxes, which would be set at a much higher rate than Ireland's, are also opposed by European commissioner for the internal market and services Charlie McCreevy.

"The idea is so bizarre. These are all still sovereign nations," Mr Ellison said. He didn't understand why some leaders in the EU felt independent member states shouldn't be allowed to choose their own tax regimes and noted that individual US states pick their own taxation systems.

"You see what works in different places. Over here, [ low corporate taxes are] really working well for Ireland," he said. "And a low tax rate doesn't mean low taxes. When you lower the rate, taxes often go up; when you raise rates, revenue goes down."

Though it was criticised at the time, US president George Bush's tax cut had increased tax revenue, he said.

Speaking on what he sees as the success of Ireland's low-tax regime, Mr Ellison added: "I think it's great." He added now that France's former president, Jacques Chirac, one of the more ardent supporters of European tax harmonisation, had left office, the EU might now abandon such plans.

However, Mr Ellison said restrictive visa policies could prove to be a serious impediment to economic growth and innovation. Oracle would be "idiotic not to source labour all over the world. But the US was becoming more difficult about giving visas. So they educate engineers [ who come to US universities] and then throw them out of the country," he said.

"My belief is people who have certain talents that are in short supply and high demand should get preferential treatment. If those people want to go to Ireland, they should be welcomed.Decisions on visas and immigration often are not rational but get caught up in politics."