Elite New York firms Simpson Thacher & Bartlett and Sullivan & Cromwell have bagged plum roles on the $45bn (£23bn) leveraged buyout (LBO) of utilities giant TXU – potentially the largest LBO to date.

Simpson Thacher is lead adviser to the bidding consortium, comprising private equity giants Kohlberg Kravis Roberts & Co (KKR) and Texas Pacific Group, which is being advised by Cleary Gottlieb Steen & Hamilton.