China is on a third "white list" of jurisdictions that have substantially implemented the internationally agreed tax standards. But the OECD said China's two Special Administrative Regions of Hong Kong and Macao had so far only "committed to implement the internationally agreed tax standard."

Earlier, the G20 pledged to take action including sanctions against non-cooperative jurisdictions, including offshore financial centres, using information from the OECD as its basis. Details of any specific measures that OECD members might take against tax havens have not yet been spelled out in detail.

Although exact figures are hard to obtain, some estimates of offshore money say up to $11 trillion is held in such jurisdictions, although other estimates are considerably lower than that.

Defenders of such offshore locations say they provide otherwise high-tax countries with an incentive to keep tax rates down, give shelter to groups fleeing rapacious and oppressive regimes, and are also convenient financial hubs in a world where many people move around with their work. Some jurisdictions, such as Switzerland, have argued that OECD member states such as the UK are anyway being hypocritical on the issue because they are tax havens themselves.

Switzerland, which has the single largest share of offshore money, said yesterday that it has put into motion plans to cooperate with the OECD standards. In recent weeks, jurisdictions such as Switzerland, Liechtenstein and Singapore have endorsed OECD standards on exchanging information. However, Switzerland continues to insist that its centuries-old tradition of bank secrecy is intact. To change such secrecy laws will require domestic legislation on rooting out tax cheats, but critics questioned whether that would sufficiently dismantle banking secrecy as demanded by the Group of 20 economic powers.

Liechtenstein, Switzerland's tiny Alpine neighbor, said it has already started negotiating with British officials and is ready to implement tough new standards.

The two countries are among a number of offshore banking centers that have accepted new guidelines in recent weeks as part of the campaign by the United States, Germany, France and Britain to crack down on tax evaders stashing their money abroad.

Swiss President Hans-Rudolf Merz was reported as saying that he welcomed measures agreed at the G20 meeting in London to spur economic recovery and could see that "the question of banking secrecy and administrative assistance in tax questions is receiving the highest attention."

The Swiss Bankers Association regretted the listing of Switzerland in the grey area.

" Switzerland doesn't belong on such a grey list," spokesman Thomas Sutter was quoted as saying. "It had accepted all the measures that were demanded by the G20 countries before the meeting."

Nonetheless, Sutter said, the Swiss Bankers Association will support the Swiss Cabinet in the upcoming negotiations for tax treaties with other countries.

Max Hohenberg, spokesman for the Liechtenstein government, said: "We have already declared that we will accept the OECD standards, so we view this announcement with a certain calmness. For Liechtenstein it's simply a matter of implementing the standards. We want to resolve this issue once and for all."

China opposed labeling Hong Kong and Macao as tax havens in a list proposed at the G20 summit, Chinese Foreign Ministry spokesman Qin Gang was quoted as saying.

" China actively supports the international community's efforts to tighten financial regulation, crack down on tax evasion, and international cooperation to prevent tax evasion,” he was quoted as saying.