Citigroup is being sued by shareholders of a bankrupt Mexican company, who claim the bank's loan arrangements contributed to the company's failure, Bloomberg reports. Investors and creditors lost more than US$1 billion as a result of the collapse of the oil industry service company Oceanografia in 2014. Investors say Citi colluded with the company, accepting falsified financial statements to support short-term loans. Royal Bank of Scotland has reported a loss of £1.9 billion for 2015 - its eighth straight year of losses, the BBC reports. The bank is still putting aside billions to cover past mistakes and fines, including a £3.6 billion charge to cover conduct and litigation costs. It also set aside £2.9 billion for restructuring, as it prepares to withdraw from 25 of the 38 countries where it operates.