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SINGAPORE/HANOI, April 9 (Reuters) - China's CDH Investments said on Tuesday it completed an investment for a minority interest in grocery chain Bach Hoa Xanh, a unit of Vietnam's biggest retail group by market value Mobile World .

The deal valued is 1.8 trillion dong ($72.17 million) and represents 5% of the firm's charter capital, showed a letter to CDH from the Ho Chi Minh City investment department seen by Reuters.

CDH and Mobile World did not immediately respond to requests seeking comment on the valuation.

The announcement confirms a Reuters' report in February saying that CDH, one of China's biggest alternative investment firms and also a former Mobile World investor, was in advanced talks to buy a minority stake in Bach Hoa Xanh.

Beijing-based CDH did not disclose financial details of the investment but said Mobile World will remain the controlling shareholder of Bach Hoa Xanh, next to CDH and the company's management.

"Vietnam is one of CDH Southeast Asia's priority markets," said Thomas Lanyi, head of Southeast Asia for CDH.

"Consumer needs are evolving in favor of modern alternatives to traditional wet markets and Bach Hoa Xanh is ideally positioned to capture this potential," he said in a statement.

Bach Hoa Xanh, which specialises in selling fresh food and vegetables, commands a network of around 1,700 stores across southern and southcentral Vietnam, the companies said.

Shares in its parent Mobile World were up 1.4% in morning trade.

CDH, co-founded by Chairman Wu Shangzhi in 2002 as one of China's earliest private equity firms, is best known for its dealmaking in traditional industries such as consumption and manufacturing.

It has over $27 billion in assets under management and has been an investor in pork supplier WH Group and appliance maker Midea Group, its website showed. ($1 = 24,940.0000 dong) (Reporting by Yantoultra Ngui in Singapore and Phuong Nguyen in Hanoi; Editing by Muralikumar Anantharaman)