Shawbrook is majority-owned by a fund run by RBS's equity finance arm, and the Edinburgh bank also holds a 13% stake.
However, the Essex institution remains independent of RBS and has its own banking licence.
Mr Henderson said: "I am starting to sound out investors now. There is a lot of interest. We have high margins, we have a high return on equity.
"We are focused. The down side is we are small. We just have to show that we have the ability to generate sustainable growth and sustainable returns."
Perthshire-born Mr Henderson joined Shawbrook as chief executive in November from Barclays Wealth but the vast bulk of his career has been at RBS.
Mr Henderson expects Shawbrook, which targets niche parts of the small business and retail banking markets, to turn a profit in 2013. This will ease the way to a change of ownership as RBS runs down its equity finance business as part of its restructuring and investors look for an exit.
Mr Henderson said managers of Shawbrook had "no preference" about whether the bank went for stock market flotation or sale.
"This business will be under different ownership in the next two years or so," Mr Henderson said. "Listing is an option but it is one of a number of options."
The largest part of Shawbrook's book is asset finance for business purchases such as vehicles. It bought Singers Asset Finance, formerly owned by bust Icelandic Bank Kaupthing, last year.
It also has a commercial lending business that backs trading businesses acquiring premises and professional buy-to-let investors with up to 30 properties.
It offers secured second mortgages and most recently has started providing loans to consumers through the likes of home improvement companies.
Currently, it is lending between £40 million and £50m a month and expects to see that rise to £80m by the end of the year.
"Shawbrook doubled in size last year. We will double this year. It is not often you get the chance to do that," Mr Henderson said.
The bank employs 250 people and this number is expected to increase by 30% over the next year.
Alongside Sir George on the board as deputy chairman is Sir Brian Ivory, former chief executive of Highland Distillers who previously sat on the board of Halifax Bank of Scotland. Others include Lindsey McMurray, head of equity finance at RBS, and Robin Ashton, former chief executive of defunct London Scottish Bank.
Mr Henderson has long-standing ties to Sir George, having worked for him at the Scottish Development Agency and followed him to RBS. He held senior roles including head of group marketing for the RBS and NatWest brands.
He went on to run Guernsey-based RBS International, jumping ship in 2010 after the credit crunch nearly brought down the Scottish group.
He said there were many benefits of working for a smaller institution.
"We can come up with a product and launch it 10 days later," he said.