European stocks have struggled as investors fret over the global impact of the eurozone crisis and poor US earnings, but sentiment has been partly boosted by a new Spanish austerity package.

At the close, London's FTSE 100 index of top companies was unchanged at 5664.48 points. In Paris the CAC 40 fell 0.57 per cent to 3157.25 but Frankfurt's DAX 30 index eked out a 0.25-per cent gain at 6453.85 points.

Madrid bounced into positive territory as dealers welcomed the Spanish government's vast 65 billion euros ($A78.63 billion) austerity package aimed at stabilising the public finances. The IBEX 35 index rose 1.17 per cent to 6805.9 points.

However, Italy's stock market edged lower on persistent worries that debt-laden Rome may have to tap a eurozone rescue fund. The FTSE Mib index was off by a slight 0.05 per cent at 13,861 points.

"Global growth storm clouds continue to gather," commented dealer Jonathan Sudaria at the trading group Capital Spreads.

The euro meanwhile dipped to $1.2242. That compared with $1.2251 in New York late Tuesday, when it had slumped to $1.2235 - the lowest point since July 1, 2010.

In Berlin, Germany's finance minister urged the country's top court to rule quickly on legal challenges to euro crisis-fighting tools.

"We have asked the court to decide as quickly as possible because we are in an extraordinarily critical situation. The risk of contagion to the whole eurozone is very high," Wolfgang Schaeuble told German radio.

In Madrid, coal miners threw rocks, bottles and firecrackers at riot police who fired rubber bullets as tens of thousands protested mining subsidy cuts.

Spanish Prime Minister Mariano Rajoy had earlier unveiled the massive austerity package to avert financial collapse.

In New York, markets edged mostly lower in midday trading, with the Dow Jones Industrial Average down 0.20 per cent to 12,627.61. The tech-rich Nasdaq fell 0.44 per cent to 2889,64 and the broader S&P 500 was flat at 1340.87.

Mike McCudden, head of derivatives at Interactive Investor, said: "It's risk-off time once again as the latest batch of US earnings brought home the impact of depleted confidence and a slowing global economy.

"This will no doubt usher in yet another round of (stimulus) chatter but in the face of continued eurozone woe, with leaders evidently not in a hurry to get the job done, investors will feel safer investing their cash under the mattress."

Investors remained sceptical about an agreement by eurozone finance ministers to channel 30 billion euros this month to Spanish banks and give Madrid an extension on a deadline to cut its public deficit.

Market sentiment was also battered on Tuesday after Italian Prime Minister Mario Monti said that Rome might one day ask for the eurozone rescue fund to intervene in its bond market in order to ease his country's borrowing costs.

"It is very difficult to say that Italy will never need help from one fund or another and caution compels me not to talk about such things," Monti said, having previously insisted that Rome did not need such an intervention.

Monti stepped down as finance minister on Wednesday to be replaced by the current deputy minister Vittorio Grilli, but signalled he would keep a tight grip on economic policy.

Asian markets were mixed on Wednesday as investors paused for breath following recent volatile trade.

Hong Kong added 0.12 per cent and Shanghai gained 0.51 per cent, while Tokyo slipped 0.08 per cent.

Concerns about China weighed on markets as investors awaited more key data later in the week, including second-quarter GDP, to gauge how fast the world's second-largest economy is slowing.

Dealers were also looking to the release of minutes from a US Federal Reserve meeting due on Thursday to determine if a third round of so-called quantitative easing, the pumping of cash into the economy, is in the cards.

AFP