* Underlying pretax profit up 68 percent to 54.5 mln stg
* Loan book grows by 23 percent to 2.9 billion pounds (Adds detail)
By Lisa Barrington
LONDON, Nov 5 (Reuters) - New British bank Shawbrook said its underlying profit rose by 68 percent duringthe first nine months of 2015, driven by growing demand fromsmall businesses for loans.
Founded in 2011, London-listed Shawbrook is one of several"challenger banks" to emerge since the financial crisis to filla gap in small business lending which appeared when larger banksslimmed down to focus on bolstering their capital to meettougher regulatory requirements.
Lawmakers and regulators have also been keen to see newbanks challenge Britain's biggest four lenders - Royal Bank ofScotland Lloyds, HSBC, and Barclays - which make 9 out of every 10 business loans.
Underlying pretax profit rose to 54.5 million pounds ($84million) during the period, up from 32.5 million pounds in thesame period a year earlier.
The bank's loan book grew 23 percent to 2.9 billion pounds.
"The group continues to deliver strong growth, withoriginations and loans to customers up 27 percent and 23 percentrespectively, driven by growing demand for lending from UK SMEs(small and medium enterprises)," Shawbrook Interim CEO and CFOTom Wood said.
"Commercial mortgages, asset finance, secured and consumerdivisions performed particularly well, both in terms oforiginations and new product launches," Wood added.
Shawbrook maintained its net interest margin at 6.1 percentin the first three quarters of 2015.
The bank said it remains well positioned to deliver its nearand medium term targets. (Reporting by Lisa Barrington; Editing by Matt Scuffham)