Extra British regulations and taxes on banks could cost Standard Chartered Plc more than $500 million (323 million pounds) a year and the industry is at risk from an avalanche of new rules, the Asia-focused bank's boss said on Wednesday.

It's easy to get to a number north of $500 million a year, said Chief Executive Peter Sands, when asked by lawmakers to estimate the cost in extra regulations of being based in Britain.

That includes the UK banking levy, which will cost Standard Chartered about $190 million this year.

I am concerned that there is an avalanche of new regulations ... there is a real danger in the quantum and complexity of regulatory change, Sands said.

That trend had increased the argument for the bank to move its headquarters away from London, an issue which is constantly under assessment, he said.

We get asked about our intentions on domicile in almost every single investor meeting, including in those with our UK investors, Sands said. Forty percent of its investors are based in Britain.

We don't have plans to leave, our preference remains to stay here in UK, he said, but added: The strength of argument to leave has grown.

Sands, being quizzed by UK politicians on reforms proposed by the Independent Commission on Banking (ICB), said his biggest concern is the plan to force banks to hold debt that can absorb losses for all of its assets.

Sands said he supported potentially making bondholders take losses if a bank fails, but the ICB's proposal was flawed in maths and logic and Britain should wait for international rules on bail-in debt to be introduced rather than front-run them.

Rival HSBC has estimated the ICB's bail-in debt proposal could cost it more than $2.1 billion a year.

The ICB said its package of reforms would cost the industry up to 7 billion pounds, which Sands said was likely to be an underestimate.

(Reporting by Steve Slater and Sudip Kar-Gupta; Editing by David Holmes)