Citi said it is reorganizing its Asia-Pacific operations into four geographic areas as regional chief Ajay Banga refocuses a business that has the fastest revenue growth in the giant US firm.

On the wealth management side of Citi’s operations, Aamir Rahim will head the region's global wealth management group, from his previous post as co-head of fixed income, currencies and commodities, Citi said in a statement.

In July, Citi announced that Kaven Leung had resigned as head of Asia-Pacific wealth management business. He had been with the bank for more than 20 years, and had become chief executive of the Asia-Pacific wealth management group last year. The unit includes the private bank and the Smith Barney retail brokerage.

Mr Leung was managing private bankers in Australia, Hong Kong, Taiwan, China, Korea, Philippines, Singapore, Malaysia, Brunei, Indonesia, Thailand, Vietnam and India.

Deepak Sharma, who heads Citi's global wealth management outside the US, took on the additional responsibility of chief executive Asia-Pacific at the time of Mr Leung’s departure.

The departure of Mr Leung came three months after Tan Su Shan rejoined Morgan Stanley in Asia after leaving her role as head of Citi Private Bank’s wealth management business in Singapore.

The Wall Street-listed bank is making the changes after Citigroup chief executive Vikram Pandit called for more local executives to make decisions without waiting for approval from the headquarters in New York. The geographic areas will be supported by seven product groups.

Asia-Pacific contributed 13.8 per cent of Citi's revenue last year, a 33 per cent increase from 2006, as the US operations suffered from the worst housing crisis since the Great Depression. The bank has logged $55.1 billion in losses and write-downs tied to US subprime mortgages.

The changes in Asia-Pacific "will leverage local expertise and thinking, eliminate management layers and provide growth opportunities," Mr Banga said in an emailed statement cited by the news service.

Under the reorganization, Asia-Pacific will be divided into four regional clusters, each led by a chief executive officer and reporting to Mr Banga. Under the previous structure, there were three product groups - global wealth, global consumer and institutional clients - each with a separate chief executive reporting to global business heads in New York.

Doug Peterson will continue to lead Japan, Stephen Bird will be responsible for North Asia comprising China, Hong Kong, Korea and Taiwan, while Sanjay Nayar remains as chief of South Asia including Bangladesh, India and Sri Lanka.

The last cluster, Southeast Asia-Pacific, will be led by Piyush Gupta. This region comprises Australia, New Zealand, Guam, Indonesia, Malaysia, Philippines, Singapore, Brunei, Thailand and Vietnam.

Zhang Shengman currently president of Asia-Pacific and country officer for Hong Kong, will manage the region's network of country officers.

Mark Renton and Dan McNamara will keep their roles as heads of the investment banking business. Fixed income, currencies, commodities and equities will be grouped under the markets division, co-headed by Rodrigo Zorrilla and David Ratliff, the statement said.

Mr Banga will lead a new alternative investments product group himself. Consumer banking and global cards will continue to be led by Mr Bird while Farhan Faruqui will remain as head of corporate and commercial banking. Anthony Nappi will continue to head transaction services.