The head of RBS's investment banking arm since 2008, John Hourican, is also expected to step down.

BBC: RBS sign

While RBS was careful to state that Hourican had no role in the wrongdoing, it ultimately took place on his watch and he will forfeit his unvested bonus and the portions of his long-term compensation subject to clawbacks.

FORBES: RBS Latest To Cough Up Libor Settlement, Will Pay $615 Million