No one can argue that Jamie Dimon leaves the grunt work for his minions. On the contrary, we now know that the J.P. Morgan chief executive gets knee-deep in the bank's deals.

How do we know? Because J.P. Morgan gets sued.

On Tuesday, lawyers for Amaranth, the hedge fund that collapsed spectacularly last year after making bad bets in the natural gas market, sued J.P. Morgan for breach of contract. The bank, the fund alleges, is responsible for interfering in trades that could have saved it from its demise. It's seeking $1 billion from J.P. Morgan, which was Amaranth's adviser. (read complaint)

Amaranth claims that J.P. Morgan was responsible for $2.5 billion of the fund's $6.5 billion in losses because it interfered with 11th-hour trades with both Goldman Sachs and Citadel that could have softened the blow. Instead, J.P. Morgan executed the trade itself, at terms that were "more onerous" than the terms from Goldman and Citadel.

The complaint recounts a frenzied weekend of dealmaking in September of last year. When the Goldman deal went belly-up on Monday, the "white knight" Citadel stepped in Monday evening. On Tuesday morning, the Amaranth crew gathered in their conference room to update the status of the trade.

"To their surprise, Mr. Dimon of J.P. Morgan led the call, telling the Fund and Advisors there was a new trade, this time with Defendants," it reads.

This might be surprising if we hadn't already heard this year about Dimon's personal involvement in deal discussions that have resulted in lawsuits.

Earlier this year, a nasty spat between executives of Dow Chemical and its C.E.O. resulted in high profile firings and subsequent wrongful termination suits.

Dimon's name again appears in the legalese print, this time for allegedly implicating the two executives for holding talks with J.P. Morgan bankers to sell Dow Chemical. The executives, who claim that the Dow Chemical chief executive had a vendetta against them, were ultimately fired for holding unauthorized merger talks.

The two executives sued Dow Chemical in May. In October, one of them added J.P. Morgan as a defendant. (read complaint)

One would think that a C.E.O. of one of the world's biggest banks would delegate conference calls on trades and inter-office mudslinging to someone else. But unlike other corporate chiefs in the hot seat, at least Dimon won't be able to claim ignorance and blame subordinates if these suits make it to trial.

by Megan Barnett