Surging trading revenues at Citigroup helped to more than offset a drop in lending revenues in the third quarter as net underlying profits at the group's securities and banking division climbed by two-thirds.

Citi, one of several US banks due to report their third-quarter results this week, said today that net revenues from securities and banking - which comprises fixed income and equity markets, advisory, underwriting and private banking businesses - rose by 15% in the third quarter from the same period in 2011, to $5.6bn.