UK's Metro Bank more than doubles loan book in 2014

* Total (Swiss: FP.SW - news) lending increased to 1.6 bln stg at end 2014

* Lending to business almost half of total lending (Adds comment from chief executive, background)

By Matt Scuffham

LONDON, Jan 21 (Reuters) - Britain's fledgling Metro Bank increased lending by 112 percent in 2014 as it drew customers from more established rivals, it said on Wednesday.

Launched in 2010 as Britain's first new retail lender in more than a century, Metro (Xetra: 725750 - news) said its loan book grew to 1.6 billion pounds ($2.4 billion) in 2014. Loans to business customers made up almost half of total lending.

Customer deposits grew by 118 percent to 2.9 billion pounds.

"Throughout the year we saw substantial growth in deposits and lending and the number of personal and business customers joining the banking revolution has continued to increase," said Chief Executive Craig Donaldson.

The bank, which has yet to make a profit, made a loss after tax in the fourth quarter of 8.9 million pounds, which it said reflected investment in staff, infrastructure and technology.

The loss was lower than the 9.4 million pounds loss made by the bank in the third quarter of 2014 and represented a sixth successive quarter of declining losses.

Metro Bank was founded by Vernon Hill, a U.S. entrepreneur, and Anthony Thomson, who left the bank in 2012 and has since embarked on a digital banking venture called Atom.

Metro Bank has been championed as an alternative to Britain's "big four" lenders - Lloyds Banking Group, Royal Bank of Scotland (LSE: RBS.L - news) , Barclays (LSE: BARC.L - news) and HSBC - which account for more than three quarters of Britain's 65 million personal current or checking accounts and provide nine out of every 10 business loans.

Britain's competition watchdog is investigating the industry and lawmakers and regulators are keen for new competitors to emerge.

Metro already has 31 branches in London and the southeast of England and said it would open up to 10 more in 2015.

($1 = 0.6622 pounds) (Editing by Anjuli Davies and David Holmes)