The owner of the world’s largest brokerage business, Merrill Lynch, confirmed yesterday at the close of trading in the US that NYSE Euronext head John Thain would take over from the departing Stan O'Neal as chairman and chief executive officer, effective 1 December 2007. Mr O’Neal was the first major head to roll on Wall Street following the sub-prime debacle when October reporting revealed debt-related losses and write-downs at some of the world’s most prestigious firms. A week after Mr O’Neal’s departure, Chuck Prince announced he would vacate the Citi Group top position. Citi is still yet to announce a replacement for Mr Prince. Reports in the US said Mr Thain was in the running for the Citi post, but those reports remain unconfirmed when WealthBriefing published. Before the official Merrill announcement yesterday BlackRock chief Laurence Fink was believed to be the main contender for the top job at Merrill. John Thain is currently chief executive officer, director and member of the management committee of NYSE Euronext, and former president and chief operating officer of rival US investment bank, Goldman Sachs. Alberto Cribiore, Merrill Lynch's interim non-executive chairman and chairman of the company's search committee, said: "John Thain is the right person to become the new chairman and CEO of Merrill Lynch… He understands both the company's challenges, and as his track record shows, he appreciates the value associated with the Merrill global brand.” Mr Thain, 52, joined the NYSE in 2004. Prior to joining the NYSE, he served as president and chief operating officer of Goldman Sachs Group since July 2003 and was previously president and co-chief operating officer from May 1999 through June 2003. From 1995 to 1997 he was also co-chief executive officer for European operations at the firm.