Buy-to-let lender Charter Court Financial Services to unveil £500m flotation.

The move could give Charter Court a market value of about £500m, sources said this weekend.

It was unclear, however, how much it would seek to raise from the sale of new shares to investors.

The arrival of another UK challenger bank on the London market will come despite a slowdown in buy-to-let mortgage lending following Bank of England measures to cool the market.

Buy-to-let lenders are contending with a new set of powers recently handed to the Bank of England, such as stricter affordability checks and interest rate 'stress tests', which follows concerns about an overheating of the market.

However, Charter Court benefited from being a big user of the central bank's Term Funding Schemes, which provides cheap loans to lenders.