Merrill Lynch’s directors may be weighing E. Stanley O’Neal’s future, but one thing is already guaranteed: a payday of at least $159 million if he steps down.

Mr. O’Neal, the company’s chairman and chief executive, is entitled to $30 million in retirement benefits as well as $129 million in stock and option holdings, according to an analysis by James F. Reda & Associates using yesterday’s share price of $66.09. That would be on top of the $70 million he took home in his nearly five years on the job.

Under Mr. O’Neal, Merrill moved aggressively into lucrative businesses like the packaging of subprime mortgages and other complex debt securities. That led to a string of blow-out quarters — and blow-out paydays. Last year, Mr. O’Neal’s $46.4 million pay package made him Wall Street’s second-highest paid chief executive, behind Lloyd C. Blankfein of Goldman Sachs, who was paid $54.3 million, according to Equilar research.

But those big bets appeared to go bust this week. Merrill announced an $8.4 billion write-down, raising questions about whether Mr. O’Neal will keep his job. One thing that he surely will hold onto, though, are the giant paychecks he has collected.