Britain’s scandal-hit Barclays bank has announced 19,000 job losses over the next three years in a major shake-up of its investment division.

Chief executive Antony Jenkins revealed the bank will cut 19,000 jobs in the next three years – 7000 of them at the investment bank – and park 400 billion pounds ($723 billion) of assets in a new “bad bank”.

Barclays will shift its focus to less risky areas of the market.

“We will refocus and resize our investment bank to bring balance to Barclays,” Mr Jenkins told analysts and investors.

“As currently constituted, it is an unacceptable drag.”

Under the changes the investment bank will make up no more than 30 per cent of Barclays’ risk-weighted assets, down from 50 per cent.

The bank announced a results statement last week that showed pre-tax profit at the investment arm dived 49 per cent to STG668 million ($A1.22 billion) in the three months to March from a year earlier, hit by sliding revenue at its Fixed Income, Currencies and Commodities (FICC) trading business.

Around a quarter of the investment bank’s 24,000 employees are expected to lose their jobs in total, according to reports by the Guardian, the BBC and Sky News.

Barclays is still seeking to fix a reputation badly damaged by its role in the Libor interest rate-rigging scandal of 2012, while it has also been probed along with other banks over possible manipulation of foreign exchange trade.

The bank is reshaping itself under Jenkins, who replaced Bob Diamond as chief executive in the wake of the Libor crisis.

Diamond, who headed the investment unit before becoming CEO, was one of the world’s highest paid bankers before and after the global financial crisis and helped to turn Barclays into a global player in investment banking.