The challenger bank where Sir George Mathewson is chairman has announced plans to float of the stock exchange.

Shawbrook, which was set up in 2011 with the acquisition of Whiteaway Laidlaw Bank from Manchester Building Society, could be valued at close to £1 billion.

It will raise £90 million from the move with a number of existing investors, including the Pollen Street Capital fund once backed by Royal Bank of Scotland, likely to sell some of their holdings.

Shawbrook predominantly specialises in commercial mortgages, asset finance and invoice related credit to businesses, with the majority of its customers in the small and medium enterprise sector. It also has a consumer lending arm with a loan book of £227m.

The group had £2.8 billion of assets, around 105,800 lending and savings customers and more than 460 employees by the end of 2014.

Net loans had grown by close to £1bn during the year to stand at £2.33bn in December while underlying pre-tax profit had almost trebled to £49.1m.

The bank has its headquarters in Brentwood, Essex with a network of nine offices around the UK of which Glasgow is the only one in Scotland.

Sir George and fellow Scottish financial veteran Sir Brian Ivory, who was a non-executive at Shawbrook but will not continue on the board through the flotation, both have shares in the bank.

It was confirmed that Sir George, the former RBS chief executive and chairman, will stay on at Shawbrook through the flotation process but step down once a new chairman has been found. The 75-year-old has been with Shawbrook since its formation in 2011.

Chief executive Richard Pyman, formerly of Singers Asset Finance, and chief financial officer Tom Wood will remain in their current posts.

Mr Pyman said: "A public listing makes strategic sense to support the next stage of our growth. It will allow us to maintain prudent capital levels as we continue to increase our market share in existing segments and deliver on the strong demand we are seeing for our proposition and fresh approach.

"In addition the capital raise will facilitate possible future expansion into new sectors. We have already established a strong record in identifying areas of the market which are currently underserved by traditional UK banks."

The non-executive directors include Graham Alcock, who spent 37 years with RBS, Leeds Building Society chairman Robin Ashton along with former Santander and HSBC executive Roger Lovering.

Pollen Street Capital managing partner Lindsey McMurray, a former head of RBS equity finance and a Strathclyde University graduate, is also on the board as a non-executive.

Shawbrook hopes to complete the flotation in early April.