Top Wall Street law firm Sullivan & Cromwell is to take the lead in representing Goldman Sachs against the formal investigation brought by the Financial Services Authority.

The investment bank had already retained Sullivan & Cromwell to defend it against fraud allegations brought by the Securities and Exchange Commission and today said the legal giant would at least for now be taking charge of the FSA case.

Goldman has a long-term relationship with Sullivan & Cromwell. Fabrice Tourre, the Goldman trader named as a defendant in the SEC's civil suit, is being represented by Allen & Overy.