Sullivan & Cromwell has been drafted in to advise Microsoft on its landmark $44.6bn (£22.7bn) attempted takeover of internet giant Yahoo! after New York rival Simpson Thacher & Bartlett was conflicted out.

Simpson Thacher last week confirmed that it had been forced to withdraw from the deal due to a conflict that could not be resolved. The firm had initially been handed the lead role for Microsoft, as reported by legalweek.com (4 February).