Huaneng Power International Inc, the publicly traded unit of China's largest electricity producer, said on Jan 28 that it expects annual net profits in 2012 will increase by more than 340 percent from the 1.27 billion yuan ($202.2 million) in 2011 based on Chinese accounting standards, the company said in a preliminary estimate.

The estimated profit surge was primarily owing to the carryover effect of the tariff adjustments in 2011, the decrease of coal prices in 2012 and effective cost controls by the company.

The company will disclose 2012 earnings on March 20.