Procter will leave the FSA in April to become head of compliance for the German bank’s London operation.
He was closely involved in the FSA investigation into endowment misselling at Legal & General that resulted in a 1.1m fine which is being contested at a financial services and markets tribunal.
Procter also led the assault on market abuse and was expected to head investigations into firms involved in the split-capital debacle.
Chief counsel David May will take on the post while a permanent replacement is being sought.
FSA chief executive John Tiner, says: “Andrew has done a superb job for us as director of enforcement and I am sorry to see him go.”
Procter says: “I have had four hugely enjoyable and challenging years at the FSA. I will particularly miss the talented people that I have worked with here.”