The Royal Bank of Scotland says it made a net profit of 1.42 billion pounds ($2.39 billion) in the first half of the year, up from 535 million pounds in 2013, as it warned that Scottish independence could dent its business.
Half-year results also showed pre-tax profit nearly doubled to 2.65 billion pounds.
RBS was rescued by the British government during the 2008 financial crisis and remains 81 percent taxpayer-owned.
The results exceeded analysts' expectations, but the bank's shares fell 2.3 percent Friday in a broadly weaker market. They soared last week after RBS released some of the numbers in advance.
The bank said a "yes" vote in Scotland's Sept. 18 independence referendum "would have a material adverse effect on the group's business, financial condition, results of operations and prospects."