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HONG KONG/SINGAPORE, April 22 (Reuters) - European investment company Permira has begun the process for the sale of its 50% stake in Asian aquatic food provider Grobest, targeting a valuation of about $1 billion for the Taiwan-based company, said three sources close to the matter.

Permira, which manages about 80 billion euros ($85.28 billion) of global assets under private equity and credit funds, has hired Morgan Stanley to run the process, expecting non-binding bids by the end of the first week in May, one of the sources and a fourth person said.

A company backed by Permira funds acquired a 50% stake in Grobest in 2018 for an undisclosed sum. One of the sources said the stake cost Permira about $400 million.

A shareholder group led by Grobest's CEO and chairman holds the remaining 50% and could be open to sell its stake in the sale, which would result in the buyer controlling the company, said two of the sources, who all declined to be named because the information is confidential.

Grobest does not disclose its financial performance on its website but its expected annual revenue is about $1 billion, one of the sources said.

London-headquartered Permira, and Morgan Stanley declined to comment. Grobest did not immediately respond to a Reuters request for comment.

Founded in Taiwan in 1974, Grobest focuses on research and development of natural, antibiotic-free feed products for environmentally friendly and sustainable aquaculture.

The company now has over 3,000 employees, with offices and operations in China, India, Indonesia, Malaysia, the Philippines, Taiwan, Thailand and Vietnam, its website says.

Permira has been investing in Asia for 19 years, having deployed more than $4.5 billion in the region. Besides Grobest, its current investments in Asia include Australia' largest diagnostic imaging services firm I-MED and Hong Kong-headquartered aircraft part and services company Topcast, its website showed. (Reporting by Kane Wu in Hong Kong and Yantoultra Ngui in Singapore; Editing by David Goodman and Muralikumar Anantharaman)