European Union finance ministers have agreed to tighten rules for hedge funds in a a move that some fear will block US funds from the region and cause the industry to flee London where 80 per cent of European funds are located.
The ministers, meeting in Brussels, also pledged new taxes on banks and to defend the integrity of the eurozone as a viable economic union.
The new EU rules would regulate managers of hedge funds, private equity, property and commodity funds for the first time, requiring them to register with regulators and hand over information on their trades.
In common with banks, they will also have to set aside capital to counter risks.
Hedge funds are lightly regulated investment vehicles that cater to rich and institutional investors.
They promise high investment returns but are often risky and tend to use complex trading strategies.
The new measures, which put hedge funds under the eye of a pan-European watchdog for the first time, are part of a wider set of pledges by world leaders to create a more stable financial system after the global economic crisis.
Crucially, the proposed rules do not give funds the automatic right to sell across the 27-nation EU bloc.
Instead, funds who want to market to the EU will have to qualify through a new passport-style system.
Tim Geithner, the US treasury secretary, has complained that this is a "protectionist" move that could shut his country's funds out of the continent.
The ministers will now negotiate with the European Parliament to decide the final details of any legislation which is due to come into force from 2012.
Wolfgang Schaeuble, Germany's finance minister, said: "We must go beyond the stage of announcements, declarations of intent and testing, and implement facts.
"It must be made clear that policy makers set the rules, not the markets."
Reporting from Brussels, Samah El-Shahat, Al Jazeera's economics analyst, expressed doubt that changes to rules for banks and hedge funds will be enough to stem fundamental economic problems.
"The eurozone foundation is rotting because of the design of the euro," she said.
"Having a one size fits all policy does not work."