LONDON — A rogue trader who lost $2.2 billion in bad deals at the Swiss bank UBS was sentenced to 7 years in prison Tuesday after being convicted in what prosecutors called the biggest fraud case in the history of British banking.

Kweku Adoboli, 32, exceeded his trading limits and failed to cover losses, faking records to hide his tracks at the bank’s London office. At one point, he risked losses up to $12 billion.