Challenger bank Aldermore will have a market capitalisation of around £800m when it floats on the London Stock Exchange later this month.
Aldermore, which focuses on lending to small and medium-sized businesses and homeowners, has set its offer price at between 217p and 265p per ordinary share.
It hopes to raise £300m of fresh funds.
Final pricing is expected to be announced on or around October 17, with the start of conditional dealing to begin on the same day.
Chief executive Phillip Monks said becoming a public company is the "natural next step" in Aldermore's evolution.
"It positions us for the next stage of our development through greater access to the capital markets and enhanced profile for our brand", he said.
Aldermore reported profit before tax of £18.6m for the six months ended June 30 2014, an increase of 249% on the profit before tax of £5.3m for the first half of 2013.