Dubai: Many Islamic retail banks do not provide services that cater to an increasing number of Sharia-compliant customers, according to Barclays.

Only a "handful of simple" products, such as savings accounts, Islamic loans and debit cards are available to the world's 1.6 billion Muslims, Harris Irfan, the Dubai-based head of Islamic finance products at Barclays Capital and Barclays Wealth, said.

Barclays, the UK's second-largest bank, began offering Islamic retail products such as murabahah deposits, insurance and investment services in 2009, according to the bank.

"A Sharia-compliant customer only gets a fraction of what a conventional customer has access to," said Irfan.

"We're almost at that Stone Age phase of sticking your money under the mattress."

Demand for Sharia-compliant products is increasing as the wealth of Muslims rises, spurred by export-led Asian economic growth and crude oil income in the Gulf.

Created in the 1970s, the Islamic finance industry's assets may quadruple to $2.8 trillion (Dh10.2 trillion) by 2015 from about $700 billion in 2005, according to the Kuala Lumpur-based Islamic Financial Services Board.