The US member firm of Andersen Worldwide, which was once the fifth largest auditing firm in the country, told the US Securities and Exchange Commission it would cease auditing public companies.

It already had given up its licence to practice in several states. The Chicago-based company counts fewer than 3,000 of the roughly 28,000 employees it employed before the Enron scandal. In June, the 89-year old company was convicted of obstruction of justice for shredding and doctoring Enron documents.

'As of this day, Arthur Andersen LLP has voluntarily relinquished, or consented to revocation of, its firm permits in all states where it was licensed to practice public accountancy with state regulators,' the company said in a statement.

The firm is expected to be sentenced on 17 October.