Shares of Vertex Communications and Technology Group extended their gains yesterday on news the media firm planned to team up with an investor for its foray into Hong Kong's power sector. The stock closed 7.54 per cent higher at 57 cents yesterday after jumping 12.76 per cent on Tuesday. The share price has risen 21.27 per cent since Monday. Brokers said investors were betting on an alliance with China Southern Power Grid, one of the mainland's two state-owned power grid operators, as a strategic shareholder of China Hong Kong Power Development, a 30:70 joint venture between Vertex and China Power International Holdings. Vertex would only say yesterday that it was in talks to introduce an investor to the joint venture, which aims to import electricity from lower-cost Guangdong to Hong Kong. 'The stock is highly speculative,' said Shenyin Wanguo Securities associate director Steve Cheng Ka-wah. '[Vertex] has not yet revealed its business plan. Even if it materialises, it won't be easy to break even in the short run as electricity distribution networks are held by CLP and Hongkong Electric.' He added that China Hong Kong Power must first overcome the regulatory issue, with the scheme of control governing rates remaining in effect until 2008. Market sources said Vertex's plan to bring in a strategic investor would help resolve the distribution and transmission problem as state-owned China Southern Power Grid's network spanned five southern provinces including Guangdong. The Guangdong power grid is linked with CLP's. The Hong Kong government said China Southern Power officials paid a 'courtesy visit' recently to the Economic Development and Labour Bureau to exchange views.