Metro Bank, launched in July as Britain's first new high street retail bank in more than 100 years, said it had raised £50m of new capital from investors to further develop its business.
The latest round of capital raising builds on an initial £75m raised earlier this year, and the company said the new cash will help it increase the number of new branch openings over the first 2 years to at least 18 from 12.
"The completion of our second round of capital raising is a a result of our hugely successful launch and the opportunity to accelerate our roll out," Metro Bank co-founder Vernon Hill said in a statement.
Metro Bank is one of several new entrants seeking to break into the UK retail banking sector, which is dominated by the "Big Four" of Lloyds, Barclays, HSBC and Royal Bank of Scotland , following the credit crisis.
The company, whose investors include fund management company Fidelity and property investors the Reuben brothers, has said it may consider a stock market listing in 2013