The Royal Bank of Scotland says its group finance director Nathan Bostock has “informed the board of his intention to resign”, less than three months after taking the role.

RBS said Nathan Bostock, who was appointed to the post on October 1, informed the board of the taxpayer backed-bank of his intention to resign on Tuesday evening.

An RBS spokeswoman said: “The Royal Bank of Scotland Group can confirm that Nathan Bostock has this evening informed the board of his intention to resign from his role as Group Finance Director.

“His formal resignation is expected soon, but he will remain in his position to oversee an orderly handover of his responsibilities.

“Details on arrangements for his successor will be announced in due course.”

The news of Bostock’s departure from RBS comes a week after IT problems left some customers unable to use their debit or credit cards or access their accounts.

RBS chief executive Ross McEwan admitted that it had failed to invest properly in systems for decades after a computer glitch left customers of RBS and its NatWest subsidiary unable to use cards for three hours on the busiest online shopping day of the year.

Days later RBS said its websites were the victim of a cyber attack that caused the group’s sites to go down and left some customers unable to access their accounts.

Sky News reported that Bostock was on the verge of joining Spanish bank Santander.

RBS, currently 81-per-cent-owned by the British government after the world’s biggest bank bailout following the 2008 financial crisis, was recently hit with a 391 million euro ($A594.45 million) fine by the European Union for rigging key interest rates.