BILLIONS up in flames, allegations of dope smoking and of playing golf and cards while the empire burned; it’s a terrible way to end a career. Now to make matters worse, Jimmy Cayne, fallen boss of Bear Stearns, has been publicly lambasted by his mentor, with whom he still shares an office.

Bear Stearns was the biggest Wall Street casualty of the credit crisis. In March the bank ran out of money when investors withdrew more than $10 billion (£5 billion) in a single day, spooked by the firm’s exposure to mortgage-related securities. Now it is being taken over by

JP Morgan and as many as 10,000 of Bear’s 14,000 staff could lose their jobs.

Among their number is Cayne, who also lost $900m as the bank’s share price fell. Not that his former boss Alan “Ace” Greenberg has much sympathy.

“Oh really? Goodness, that’s a shame,” Greenberg told The New York Times last week. Subsequent comments suggest he was being sarcastic.

Greenberg, a Wall Street legend, delivered several body blows in the interview. The octogenarian who has been with Bear Stearns for 59 years said

he tried to warn Cayne of the impending credit crisis last summer. He claimed: “Jimmy was not interested in my point of view. He was a one-man show — he didn’t listen to anybody.”

The two were once friends and bridge partners. Not any longer. “I don’t understand why he still comes in. He’s not employed here anymore,” said Greenberg. He rubbed salt into the wound by charging Cayne $77,000 commission on the sale of 6m Bear shares. Bear usually charges employees a maximum commission of $2,500.

“If he doesn’t like it, he should do his business elsewhere,” said Greenberg, who is now writing his memoirs — a book that will be as eagerly awaited by Wall Street as it will by Cayne’s lawyers.

Greenberg and Cayne have had a complex relationship that stretches back over 40 years. Jordan Belfort, author of The Wolf of Wall Street, an autobiography of his own spectacular Wall Street rise and fall, first knew the pair in the early 1990s.

“Ace is a really great trader. Everybody likes him. Cayne had the reputation of being a bastard,” said Belfort.

He said the struggle between them was typical of the struggle between traders and salesmen. Greenberg wanted to hedge his risk, make sure the bank was safe. Cayne wanted to make the sale — risk or no risk.

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