Bank of America has been banned from suing Parmalat, the food group which went bust in 2003 after an accounting scandal.
The bank – along with investors, auditors and the group’s managers – want damages for being victims of fraud at the hands of the Italian firm.
But a judge has barred Bank of America and two auditors from the case.
The bank, and Italaudit – formerly the Italian arm of auditor Grant Thornton – face lawsuits and possible prosecution.
A second auditor, Deloitte & Touche, has also been banned from the case.
Grant Thornton – now rid of the Italian unit at the centre of the case – is still being permitted to sue, as are Consob, Italy’s stock market regulator, hundreds of small investors and Parmalat’s new managers.
Parmalat collapsed in December 2003 after it emerged that the 4bn euros ($5.2bn; £2.8bn) it supposedly held in a Bank of American offshore account did not in fact exist.