An IT and marketing investment of £6 billion at the Royal Bank of Scotland is crucial to the group's future, according to its chief executive.

“You cannot generate shareholder returns without investing in technology," Stephen Hester told an audience at the Sibos conference, according to a report by the Finextra website.

Last October the bank announced the £6 billion investment, which included the move to a group-wide undisclosed technology platform. RBS has not responded to calls for further detail.

Hester said last year that the bank had been “built as an acquisition machine”, comments thought to refer in part to the RBS-led acquisition of ABN Amro in 2007 for £48 billion, the largest acquisition in European banking history.

As a consequence, Hester said, quality had been “neglected through a series of distracting business integrations”. The bank, he said, was struggling with running “lots of different systems”.

RBS, which is 84 percent state-owned, has been extensively cutting jobs. In September, it announced 3,500 job cuts from its UK-based technical and back office division.