"The growth achieved by Masraf Al-Rayan in 2010 includes the overall activities of the bank," said Adel Mustafawi, CEO of Masraf Al-Rayan, in an e-mailed statement.

"This growth has been driven by the bank's rapidly expanding customer base and its diversification of its services," he said.

Total assets reached 29.1 million riyals compared to 22.6 million riyals in the corresponding first half of 2009, an increase of 28.6 percent, the statement said.

Customer deposits reached  22.1 million riyals, a jump of 30.5 percent from the year ago period. The Islamic lender earned 386.5 million riyals during the first half of 2009.

Masraf Al-Rayan said in March it had launched a Gulf-wide fund to manage up to $1.1 billion and focus on Gulf equities, as well as fixed-income instruments.

Qatar's central bank said in March that banks would be allowed to diversify their revenue base and bolster trading income by buying shares of listed companies on the bourse and re-entering brokerage operations.

Qatar's economy grew at an average pace of 17.4 percent over the past five years and it is set to largely outperform fellow Gulf oil producers such as Saudi Arabia and the United Arab Emirates in coming years due to expansion of its gas facilities.

Earnings were released after trading hours on the Qatari bourse. Shares in Masraf Al-Rayan have gained 5.2 percent this year.