Under the Travelers brand, the company is also a leading underwriter of homeowners and auto insurance through independent agents.

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Leading the Facebook sale would be a huge win for Morgan Stanley, which last year cemented its position as the top Internet stock underwriter by leading the IPOs of LinkedIn Corp.

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Imagine, in JPMorgan Chase's case, the frustration at being the leading credit derivatives house, high-yield-bond underwriter and fixed-income research firm (among other things) and then losing on some bets on interest rates.

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