So when exactly does H. Rodgin Cohen sleep?

The chairman of Sullivan & Cromwell LLP continued to be in the center of the bank M&A storm as J.P. Morgan Chase & Co. paid the Federal Deposit Insurance Corp. $1.9 billion for most of the assets of Washington Mutual Inc. on Sept. 25 and Citigroup Inc. agreed to buy the banking operations of Wachovia Corp. on Sept. 29 for $2.2 billion in equity. The mandates come on the heels of Cohen's involvement in everything from the bailouts of Fannie Mae and American International Group Inc. to Lehman Brothers Holdings Inc.'s search for a savior.

Cohen's work for J.P. Morgan in the WaMu deal was a bit of a surprise, considering that J.P. Morgan used the other big name in bank M&A, Edward Herlihy of Wachtell, Lipton, Rosen & Katz, in its acquisition of Bear Stearns Cos. earlier this year. J.P. Morgan CEO Jamie Dimon also tapped Wachtell in 2004 when, as the CEO of Chicago-based Bank One Corp., he crafted a merger with J.P. Morgan, and Wachtell showed up again to advise Morgan on the $3.1 billion swap of its corporate trust unit for Bank of New York Mellon Corp.'s retail and small-business banking network in 2006.

But this time around, a source says, Wachtell was working with San Francisco's Wells Fargo & Co., which looked at both WaMu and Wachovia as potential targets.

In addition to Sullivan & Cromwell, J.P. Morgan turned to William Fogg of Cravath, Swaine & Moore LLP as counsel to J.P. Morgan Securities Inc., the sole underwriter for the $10 billion stock issuance it is planning in connection with the WaMu deal. Internally, Dimon and his CFO, Michael Cavanagh, led the deal talks, with help from a team of J.P. Morgan senior bankers, including Douglas L. Braunstein, the head of investment banking; Tim Main, global head of the bank's financial institutions group; and Therese Esperdy, global head of debt capital markets.

In looking for a buyer, WaMu was represented by its longtime outside counsel, Lee Meyerson of Simpson Thacher & Bartlett LLP, along with bankers from Goldman, Sachs & Co. and Morgan Stanley. Goldman's team consisted of John Mahoney, Todd Owen and Huntley Garriott, while Morgan Stanley's lead bankers were John Esposito and Kirk Wilson.

But those efforts were ultimately fruitless. Instead, the FDIC ended up auctioning off WaMu. TPG Capital, which saw the $1.3 billion it invested in WaMu in April disappear, used longtime counsel John "Jack" Murphy Jr., Michael Ryan and Paul Shim of Cleary Gottlieb Steen & Hamilton LLP for advice on WaMu's collapse.

One source close to WaMu notes that the FDIC kept the bank's advisers out of the loop of a parallel process it had set up to seek alternatives for the thrift. Indeed, another source says that the FDIC undermined the bank's efforts to find a buyer, as most interested parties assumed that the government would ultimately control WaMu's fate.

As Cohen and his crew were completing the purchase of WaMu's assets for J.P. Morgan, they were also representing Wachovia in its efforts to find a buyer. Cohen was a key adviser to First Union Corp. as it grew into a national player and represented the bank on its $14.4 billion acquisition of Wachovia in 2001. Simpson's Lee Meyerson represented Wachovia on that deal and continued to handle occasional assignments from the bank, including its acquisition of Prudential Financial Inc. in 2005. Meyerson worked with Cohen on what presumably will be their client's last deal, its fire sale to Citigroup.

Citigroup used lawyers at three law firms on the purchase: John Ettinger, Phillip Mills and Michael Davis at Davis Polk & Wardwell; Eric Friedman, Greg Fernicola, Bill Sweet Jr., Bill Rubenstein and Stuart Levi of Skadden, Arps, Slate, Meagher & Flom LLP; and, for advice on capital markets and disclosure, Alan Beller and Jeffrey Karpf of Cleary Gottlieb.

Citi used Sullivan & Cromwell and Cleary last fall in selling a 4.9% stake to Abu Dhabi Investment Authority for $7.5 billion. Skadden has had a long, close relationship with Citi: Partner Kenneth Bialkin was once on its board and was Sandy Weill's go-to M&A lawyer. Former Citi CEO Charles Prince is married to Skadden's Margaret Wolff, and his son is a former Skadden associate. But Vikram Pandit built his career at Morgan Stanley, whose ties with Davis Polk go back decades.