Royal Bank of Scotland will axe four out of five jobs from its investment bank over the next four years, according to reports.

The government-owned bank had already announced plans to reduce the extent of its investment banking operation from 38 countries down to just 13.

A total of 14,000 jobs will go by 2019, especially in the US and Asia, as part of CEO Ross McEwan's steamlining plan. This was first reported by the Financial Times and two people familiar with the matter were quoted by the paper.

It said RBS had set a target of cutting as many as 80% of jobs in the unit by 2019, while overhauling the back-office systems to automate them.

The bank intends to cut its risk-weighted assets in its investment banking sector by two-thirds. The move is expected to cost between £2.5bn (€3.4bn, $3.8bn) and £3.5bn.

The Wall Street Journal had earlier reported that the bank could cut more than 1,000 investment-banking jobs in the US.

The bank agreed to sell its US and Canadian loan commitments to Japan's Mizuho Bank, part of the Mizuho Financial Group, in a deal worth about $3bn, as it sets its focus "mainly on UK and Western European customers, built on existing product and service strengths."

McEwan may have been spurred on by RBS's disappointing results this week - its seventh straight annual loss. RBS recorded an annual loss of $5.4bn in 2014 after taking a write-down of more than $6bn on its US arm, Citizens Bank.

RBS's peer Barclays may also take a similar decision as CEO Antony Jenkins said his "patience would be limited in waiting for a recovery of Barclays investment bank".

However a shift away from wholesale banking will leave the UK reliant on foreign groups to provide access to capital markets, the FT added.