Shares in Guangdong Brewery soared today amid speculation about a possible overseas investment in the company. The shares rose by a third, rallying in the afternoon session in Hong Kong.

"People are speculating that an overseas party (is interested) but I've not heard any concrete details," Steven Leung, trader at UOB Kay Hian Holdings, told Reuters.

A company official could not immediately be reached for comment. Guangdong's shares closed at HK$2.70, their highest level since 1997.

Last month, Heineken was reported to be considering increasing its stake in Guangdong. Earlier this year, Heineken Asia Pacific Breweries China Pte Ltd, Heineken's joint venture with Singapore's Asia Pacific Breweries (APB), acquired a 21.5% stake in the Chinese brewer.