Stanley O'Neal has become president and chief operating officer of Merrill Lynch & Co, making him an almost certain successor to David Komansky, chairman and chief executive.

O'Neal will take up a position that has been vacant since Herb Allison resigned in 1999, having been passed over for Komansky's job. The fact that the chairman, who is expected to retire in the next few years, has finally decided to name a replacement for Allison has fuelled speculation that the search for a successor is over.