* Sale of up to $5 bln stake kicks off this week
* Foreign ownership limited to 49 pct
* Sabeco offers access to fast-growing Vietnam market
* Thai Bev seen as strong contender - sources
* AB InBev, Japanese brewers also keen - sources
By Anshuman Daga and Martinne Geller
SINGAPORE/LONDON, Dec 10 (Reuters) - Brewing groups including Thai Beverage, Anheuser-Busch InBev and Kirin Holdings are gearing up to bid for a stake in Vietnam's largest brewer, Sabeco, people familiar with the matter said, with the $5 billion sale process by the government opening this week.
The auction of up to 54 percent of Sabeco, in what is set to be Vietnam's biggest privatisation, offers brewers access to a fast-growing market with a youthful population and beer drinking culture.
Thai Bev, controlled by tycoon Charoen Sirivadhanabhakdi, is shaping up as a strong contender, the people said, as it is familiar with the Vietnam system and sees Sabeco as key to expanding outside its home market.
"They have been around this situation for many years and are very keen to get this asset," said one of the people, none of whom wanted to be named as they are not authorised to speak to the media.
Last month, a Thai Bev unit bought a 49 percent stake in a Vietnamese company which, the people said, could be used as a vehicle to bid for Sabeco as a domestic player, giving it an advantage over international rivals.
Thai Bev had no immediate comment, but said in October it was keen to grow through acquisitions in markets such as Vietnam. Firms controlled by Sirivadhanabhakdi also hold a 19 percent stake in Vietnam's Vinamilk.
A spokeswoman for AB InBev, the world's biggest brewer, said the company was committed to Vietnam and to growing its business for the long-term. A spokesman for Japan's Kirin said it was carefully considering its options.
Other potential bidders include Asahi Group Holdings , San Miguel and Heineken, though several people said Heineken already had a strong business in Vietnam and could sit out an expensive auction that values Sabeco at about 36 times core earnings - more than double the trading multiples of around 15 for some global brewers, according to Reuters data.
Heineken, which already owns 5 percent of Sabeco, did not respond to requests for comment.
Asahi could not be immediately reached for comment, but the Japanese firm's president told Reuters in September it was studying Sabeco.
San Miguel's president Ramon Ang said the Philippine conglomerate was interested to bid for Sabeco. Kirin owns around half of its affiliate San Miguel Brewery.