The latest move by Europe's biggest bank follows its retreat from Japan's top-tier private banking business, which covers clients who hold more than 200 million yen in assets, selling the business to Credit Suisse in December.

"I am writing to you today to inform you with regret that we will be discontinuing our HSBC Premier service in Japan," HSBC said in a release addressed to the clients of the service.

The decision followed its review of the company's global business strategy, it said.

Last year the company outlined a strategy in which CEO Stuart Gulliver said he wants to cut annual costs by $3.5 billion and sharpen the bank's focus on Asia by quitting countries or businesses where it lacks scale.

The bank said on Wednesday that it would stop accepting new deposits for its HSBC Premier service from Thursday.

It would stop offering new investment products to its clients through the service from March 8.

The bank plans to close a HSBC Premier branch in Nagoya, in central Japan, on April 27 and would close the rest of the branches on July 31.

Japan has 1.7 million millionaires in dollar terms, and is by far the single largest market for high net worth individuals in the Asia-Pacific region, accounting for 52.5 percent of the region's millionaires and 38.2 percent of its wealth at end-2010, according to the wealth report.

Japanese millionaires had assets of about $4.135 trillion at the end of 2010, the report said.

Asia is a battleground for global and local private banks competing for market share in a region that is fast outpacing the United States and Europe in economic growth.

Still, Asia's private banking industry has seen consolidation recently as the market turmoil dampens growth, and rising regulatory and staffing costs dent profitability.