FORMER US securities regulator Harvey Pitt sees little chance of success in any appeal by ex-Enron chiefs Ken Lay, pictured, and Jeffrey Skilling, found guilty last night of fraud and conspiracy, but warns that hefty sentences are unlikely to deter corporate crime on a similar scale.

Lay and Skilling are likely to spend the rest of their lives behind bars after the jury in Houston, Texas, convicted them for their part in the 2001 collapse of the energy trading giant.

The men's lawyers have vowed to appeal, but Pitt, who chaired the Securities and Exchange Commission when Enron hit the rocks, said the careful verdict by the jury, which threw out nine counts of insider trading against Skilling, finding him guilty of just one, makes an appeal unlikely to succeed. 'I think that makes the case even harder to overturn on appeal because it shows the jury understood the different counts, and they were thoughtful and careful in going through them,' Pitt told Forbes magazine.

The lasting legacy of the Enron affair is tougher new accounting laws in the US - the Sarbanes-Oxley Act.

But Pitt said it was unlikely to stop another Enron-like disaster.

'The sad truth is that everything that occurred at Enron was illegal before Sarbanes-Oxley,' he said.

More giant scandals loom in the form of executives backdating their share option packages, Pitt said. 'I am amazed that people who make as much money as senior executives do would cheat so they could make more. I believe that, therefore, the next scandal is...not whether, it's when.'