HONG KONG (Reuters) - China Resources Beer (Holdings) Co Ltd <0291.HK> said it seeks to raise HK$9.51 billion ($1.2 billion) via a deeply discounted rights offer to part-fund the purchase of SABMiller PLC's <SAB.L> stake in their joint venture.

The owner of Snow, the world's biggest selling beer brand by volume, made the announcement on Wednesday after which its shares fell to a two-and-a-half-month low.

The state-backed brewer plans to issue around 811 million new shares at HK$11.73 for each share held. That would represent a 30.76 percent discount to Tuesday's closing price.

China Resources Beer said CRH Beer, its controlling shareholder with a 51.67 percent stake, will take up its entitlement.

The brewer agreed in March to buy London-based SABMiller's 49 percent stake in their CR Snow joint venture for $1.6 billion. China Resources Beer later said it had no plans to sell a stake in the venture but was open to partnership and acquisitions opportunities.

"The beer market will be further consolidated over the medium term, and the beer business will continue to become stronger through both organic expansion and acquisitions," Chairman Chen Lang said in a statement.

The brewer will also use proceeds from the rights issue to fund expansion. It is well-positioned to capture any development and expansion opportunities, but has not identified any specific investment or acquisition opportunities, Chen said.

On Wednesday, shares of China Resources Beer fell as much as 4.4 percent to HK$16.20, the lowest since April 22, compared with a 2 percent fall in the benchmark index <.HSI>. By 0310 GMT, the stock was down 3.8 percent at HK$16.38 and was heading for its biggest daily percentage decline since January.

The brewer's net loss widened to nearly HK$4 billion ($516 million) last year from HK$161 million in 2014 due to losses in non-beer businesses hit by a slowing economy.

(Reporting by Donny Kwok; Editing by Edwina Gibbs and Christopher Cushing)