City law firms reported unprecedented levels of activity in the last two weeks of September as financial institutions called on their legal advisers for guidance in the wake of the Lehman Brothers collapse.

Firms that won business on the back of the investment bank’s demise included New York’s Weil, Gotshal & Manges, which advised Lehman Brothers on its Chapter 11 bankruptcy filing in the US, and UK firm Linklaters, which is advising administrators PwC in Europe and KPMG in Asia.