Willis said its capital markets business was "the primary driver of organic growth" last quarter, while other insurance businesses remained relatively soft. Despite being the newbie, the division has delivered $510 million in commissions and fees, representing nearly 30% of fee revenue for the entire Willis franchise during the first half of 2010.

Millwater called the division a "boutique investment bank-capital markets business" that the firm "instigated" last year. It provides risk management and M&A advisory services to insurance and reinsurance companies. Last summer, the division announced the hiring of nine executives who came from the white-shoe leagues of Bank of America-Merrill Lynch ( BAC), Goldman Sachs ( GS), Credit Suisse ( CS), Donaldson, Lufkin & Jenrette, Deutsche Bank ( DB) and UBS ( UBS).

In looking ahead for future growth with Sullivan at the head of the global business that includes capital markets, Plumeri said "we are thrilled --absolutely thrilled to have him with us today."

Said Millwater: "Frankly, in my 25 years I've been in awe of Martin Sullivan... He has huge experience in the business, a huge knowledge of all the ingredients that make up the pieces that you have to bring to bear on a global multinational client."

Sullivan may bring four decades of experience to the table, but Willis Group shareholders have to hope he learned something during the three years of AIG's boom and bust in the capital markets. He officially joined the Willis team on Monday and seems eager to make up for lost time.

"Joe has made it clear that I'm at the end of my learning period this evening and I had better start contributing straightaway," he joked on the conference call.

"I've been charged with the responsibility of really giving ... the full breadth of Willis's services to our clients around the world, both existing and new," he added. "And I look forward to doing that in the months and years ahead."

No analysts were on the conference call to ask questions about the surprise news, which first appeared late Tuesday evening on the online edition of the Financial Times. By late morning, Willis' stock was flat at $30.47 while investors digested the news.

--Written by Lauren Tara LaCapra in New York.

>To contact the writer of this article, click here: Lauren Tara LaCapra.

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