Brussels has delayed the introduction in the European Union of a radical overhaul of accounting rules for banks and insurers which yesterday came into force across most of the rest of the world outside the US.

The move follows a deep split between European financial institutions over the new rules on the way they value assets in their accounts.

Analysts say some French, German and Italian banks with large investment banking activities would be hit disproportionately by the changes, forcing them to book losses on large holdings of derivatives.

But the decision by the European Commission to delay the changes within Europe has angered other banks in the region who fear they will be put at a disadvantage to international peers.

The International Accounting Standards Board earlier published its overhaul of rules on “fair value” accounting, where assets are marked to market prices. Supporters say this makes accounts more transparent, but critics believe it exacerbated the financial crisis by forcing banks to take losses on assets when markets fell.

IASB said it had fast-tracked the changes in response to calls by the Group of 20 nations to introduce them by the end of the year. However, the European Commission said it would not adopt the changes until it had carried out an in-depth analysis. It would consider adoption in the new year. The decision means that European banks and insurers will not be able to use the new rules for their 2009 accounts while companies in more than 80 countries outside the EU will be able to do so.

The postponement comes at a time when the commission itself is in caretaker mode. Diplomats in Brussels say France is interested in the internal market commissioner's job in the next commission, which is set to start operating early next year.