Barclays said on Tuesday it intended to cut at least 3,700 jobs this year and the bank, hit by the Libor rate-rigging scandal, added that it had plunged into an annual net loss.
Barclays said it in a statement that it would "reduce headcount by at least 3,700 across the group, including 1,800 in the Corporate & Investment Bank and 1,900 in Europe Retail and Business Banking." Barclays employs 140,000 staff.
The bank reported a loss after tax of £1.04 billion ($1.63 billion, 1.22 billion euros) for 2012 compared with a net profit of £3.0 billion in 2011.
"There is no doubt that 2012 was a difficult year for Barclays and the entire banking sector," said chief executive Antony Jenkins, who was brought in to shake up the lender in the wake of the Libor scandal.
"The behaviours which made headlines during the year stemmed from a period of 20 years in banking in which the sector became too aggressive, too focused on the short-term, and too disconnected from the needs of customers and clients, and wider society," he said.
"Barclays was not immune from the impact of these trends, and we suffered reputational damage in 2012 as a consequence. Change is needed both in our industry and at Barclays," Jenkins added in a statement.
Jenkins ordered a strategic review after replacing Bob Diamond as chief executive five months ago, after the bank was fined £290 million by British and US regulators for attempted manipulation of Libor and Euribor interbank rates.
As well deciding to scrap thousands of jobs, Jenkins on Tuesday said that he would slash the bank's costs by £1.7 billion in 2015.
Last week meanwhile, Barclays said it had set aside another £1.0 billion to cover compensation for mis-selling credit insurance and interest rate hedging products, which comes on top of the Libor fallout.
And Jenkins earlier this month announced that he would give up his 2012 bonus, reported to have been at least £1.0 million, because of the bank's problems.
In another blow, Barclays recently revealed that Britain's Serious Fraud Office was probing payments made to Qatar Holding, which the bank tapped for funds at the height of the 2008 financial crisis to avoid part-nationalisation.
Libor, or London Interbank Offered Rate, is a flagship instrument used all over the world, affecting what banks, businesses and individuals pay to borrow money. Euribor is the eurozone equivalent.