Taxpayer-backed Royal Bank of Scotland announced a pre-tax loss of £1.5bn in the six months to June on Friday morning - compared to £794 million last year.
RBS also unveiled a £125 million bill to cover the cost of its IT meltdown and the group took a £135 million hit to cover the cost of payment protection insurance (PPI) mis-selling, bringing its total bill to £1.3 billion, while it took a £50 million charge to compensate small businesses that were mis-sold complex interest rate swaps.
The 80% state-owned bank racked up more than £300 million worth of charges today as it counted the cost of an IT meltdown and two mis-selling scandals.
Speaking on Friday morning RBS boss Stephen Hester told BBC Radio 4's Today programme the bank was making "good progress" despite the loss and had a "clean-up job".
"It's a pretty tough external environment but I think we're making good progress," he said.
"We have continued to make the bank safer and stronger as we clean up problems of the past."
RBS said it had dismissed a number of employees for misconduct as a result of investigations into the fixing of Libor - the interbank lending rate at the heart of the most recent scandal to rock the banking industry.
The group said it continued to co-operate with investigations but, like Lloyds Banking Group and HSBC before it, said it was not possible to measure the impact on the bank, including the timing and amount of fines or settlements.
The IT glitch that hit RBS group systems on June 19 is being investigated by an independent external counsel with the assistance of third party advisors.
The group said it has agreed to reimburse customers for any loss suffered as a result of the incident and warned additional costs may arise once all redress and business disruption items are clear. A further update will be given in the third quarter.
Mr Hester, who waived his 2012 annual bonus in light of the IT fiasco, said recent mistakes had seen the banking sector's reputation "fall to new lows".
He said: "We are in a chastening period for the banking industry. The consequences of the sector's past over-expansion are still being accounted for, probably with some way still to go.
"The mistakes and vulnerabilities carried over from that period are both financial and cultural."
Looking within the results, the group revealed a 14% slide in total income to £13.6 billion while its core banking operations saw a 19% drop in operating profits to £3.2 billion.
Staff costs were 4% lower in the period, RBS said, with employee numbers down by 5,700, driven by cuts in its markets and international banking arm.
The bank revealed a near 40% slide in its bad debt charges to £2.6 billion while total exposure to the troubled eurozone fell 8% to £218 billion.
The group said its plans to float insurance arm Direct Line on the stock exchange in the second half of this year remain on track.
Direct Line saw a 6% rise in operating profit to £219 million in the period, with significantly improved claims levels, despite the impact of more severe weather.
The bank said gross mortgage lending in the first half of the year came to £7.7 billion, with net new lending of more than £3 billion.
Gross new lending to first-time buyers was up 26% while gross new lending to UK non-financial businesses totalled £41.5 billion, of which £19.2 billion was to small-business customers.
The group remains majority Government-owned and is yet to withdraw from the Asset Protection Scheme (APS), in which taxpayers effectively insure its poorer-quality loans against future losses, while it has not resumed an ordinary dividend.
But the Asset Protection Agency, which runs the scheme, said in its interim report earlier this year, that it was preparing the way for RBS to exit before the end of the year.
It is thought that an exit from the APS would smooth the path for RBS to begin being returned to the private sector.