A record quarter of debt underwriting revenues helped ease the pain of a predicted fourth-quarter slowdown in the giant markets division at JP Morgan, which kicked off earnings season for Wall Street's largest banks today.

JP Morgan published its fourth-quarter results this morning, with the corporate and investment bank posting revenues of $7.6 billion and profits of $1.1 billion for the quarter once the impact of various accounting charges - including debt valuation adjustments - were stripped out. These figures were down from $8.2 billion and $2.2 billion a year ago.