DEALINGS in IBM shares were last night halted after the world’s biggest computer company admitted that the US market regulator had launched an inquiry into its accounting practices.

IBM told Wall Street late yesterday that the Securities and Exchange Commission was investigating the way that it had accounted for its revenues for the years 2000 and 2001.

In a statement to Wall Street, IBM said the SEC was “seeking information on certain types of customer transactions”.

While PricewaterhouseCoopers, the accountancy firm, had audited the company’s accounts over the two-year fiscal period, it made no statement on the matter last night.

The period being investigated by the SEC covers revenues for IBM totalling $88.4 billion (£54 billion) in 2000 and $85.9 billion in 2001.

However, the total amount of sales derived from the “certain customer transactions” was not clear last night.

IBM said that it believed the inquiry stemmed from a separate SEC investigation of a customer of its Retail Store Solutions unit, which sells point-of-sale products. IBM refused to name the customer.

The company said that it was co-operating fully with the inquiry, which it described as a “fact-finding investigation”. It insisted that the SEC had not yet accused the company of any wrongdoing.

In a statement IBM said it believed its business and accounting policies complied with all applicable regulations and it was committed to maintaining the highest standard of compliance relating to its financial reporting.

IBM’s accounting has come under scrutiny for several years, with some investors criticising the group for a lack of disclosure.

The inquiry comes as a separate blow for Wall Street, which had hoped that the series of accounting scandals involving companies such as WorldCom had been put behind it. While the inquiry last night appeared to be preliminary, analysts said it would do little to boost confidence in US accounting practices.

The SEC declined to comment.