CLP Holdings Ltd, Hong Kong's biggest power supplier, said revenue in the nine months to September climbed 6.9 percent as gains in commercial sales helped offset a drop in residential demand.

Revenue in the period reached HK$42.7 billion (US$5.5 billion), compared with HK$39.9 billion a year earlier, CLP said.

"Rainy weather in July and August had an adverse impact on sales," the company said.