The Confederation of British Industry (CBI) has added its voice to protests against rules that force pension liabilities to be included on balance sheets.

The FRS17 rule is claimed to make quoted companies vulnerable to swinging equity values.

Insurance Times highlighted the issue last month and reported criticism of the accounting standard by senior insurance executives and union figures.

The CBI this week voiced its own fears and called for changes to the way the rule works.

In a letter to the Accounting Standards Board, CBI director general Digby Jones said FRS17 values pension assets in a misleading way.

The CBI blames the rule for the growing number of companies abandoning final salary pension schemes.

Lloyd's insurer Cox recently closed a final salary scheme, joining other companies such as Marks & Spencer, Iceland and Ernst & Young.

Jones wrote: "It is right that the users of company accounts should have access to transparent information.

"But FRS17 is misleading and introduces a degree of volatility into company accounts that fails to reflect the realities of pension scheme financing."