London - The world's biggest economic powers are set to agree Thursday to a radical rewrite of the rules for global financial markets to bring them into line with the changes unleashed in recent years by fast-paced globalization.

The Group of 20 (G20) meeting of the world's most advanced and emerging economies in London is expected to sign off on steps aimed at greater global market supervision and closing gaps in the regulatory system in an effort to bolster the global economy, as well as avoiding future crises.

But the question remains open whether the raft of reforms will meet the demands of the Europeans, who have spearheaded calls for tightening up market regulation as a way of facing up to the recession and have resisted Washington-led moves for more fiscal stimulus measures to head off the economic downturn.

Thursday's meeting will represent only the second time that the G20 leaders have met since the organization was formed two decades ago.

However, as a mark of the complications involved in implementing the market reforms, the summit leaders are expected to wind up the summit by calling for a third meeting to drive forward the changes to the regulatory system.

Comprising nations such as Britain, the United States, Germany and France as well as India, China and Brazil, the G20 represents about 85 per cent of world economic activity.

Under the G20 accord, the International Monetary Fund (IMF) is expected to be given more financial firepower to better help developing countries engulfed by economic crises and for its resources to be doubled to at least to 500 billion dollars.

Emerging economies represented at the G20, such as China, have been pressing for a makeover of the world's top financial institutions as part of an effort to reshape the global financial order and to loosen the grip of the US and other advanced nations on bodies such as the IMF.

Thursday's summit comes about six months after the G20 leaders gathered in Washington for their first meeting when they laid down the markers for sweeping market reform amid fears about the prospects of imploding global economic growth.

The London summit is also likely to agree to extend the world regulatory system, including cracking down on hedge funds as well as stepped up supervision of credit rating agencies.

At the summit, the leaders are also likely to agree to a rapid revision of the Basel II accords to help set new international standards for banking regulators. (dpa)