In a major setback for Italian prosecutors investigating the financial scandal at Italian food group Parmalat, a judge has rejected their request for a fast-track trial of 29 individuals and three financial institutions accused of financial crimes.

The judge ruled that investigators had not provided enough evidence to warrant an accelerated trial process that would have eliminated preliminary hearings, reported Reuters, citing sources.

Last week prosecutors requested the accelerated trial process for former Parmalat executives including founder Calisto Tanzi, as well as the Italian units of auditors Deloitte & Touche and Grant Thornton and financial institution Bank of America.

The prosecutors had hoped to avoid preliminary hearings, which can take years, but will now have to search for further evidence before the suspects go to trial.

All of the accused face charges of market rigging, while some are also accused of false auditing and obstructing the work of regulators.

Besides former chairman Tanzi, those named in the prosecutors' request include Tanzi's son Stefano, brother Giovanni and niece Paola Visconti, former chief financial officers Fausto Tonna, Luciana Del Soldato and Alberto Ferraris, several other members of Parmalat's board, three internal auditors, five other Parmalat executives and lawyer Gian Paolo Zini.