RPT-UPDATE 1-Huaneng Power posts Q3 profit as conditions improve

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* Huaneng Q3 profit 2.17 bln yuan vs 1.57 bln yuan consensus

* Profit surges thanks to new operating units, tariff hikes

* Shares of Huaneng down 5.7 pct in Q3, underperforming HSI

* Announces 5 bln yuan nuclear project

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HONG KONG, Oct 20 - Huaneng Power International Inc, China's largest electricity provider, swung to a third-quarter profit due to more output from new operating units, two tariff hikes in the second half of 2008 and lower coal costs.

Huaneng, like main competitors Datang Power and Huadian Power, has profited as China's power generation has risen for four months in a row on hotter-than-usual weather and after government economic stimulus measures helped put assembly lines back in motion.

China's power usage in September rose 10.24 percent from a year earlier -- the first time in 16 months that the country has posted double-digit growth in power consumption -- underscoring the strength of the economic recovery..

Huaneng's power plants, which have a generation capacity of more than 39,000 megawatts, are mostly located in China's fast-growing coastal areas.

Huaneng said separately that it would invest an estimated 5 billion yuan together with its parent firm to develop a joint venture nuclear power project in China.

"From the current and long-term perspectives, a nuclear project has a relatively better return," Huaneng said in a statement. "This capital contribution provides a good opportunity for the company to enter the nuclear sector, which is consistent with the development strategy and long-term benefit of the company."

Huaneng's third-quarter profit totalled 2.17 billion yuan for July-September, according to Chinese accounting standards. This figure compared with a restated 2.15 billion yuan net loss a year earlier, a record quarterly loss.

The result exceeded a consensus estimate for a 1.57 billion yuan profit, according to three estimates from Thomson Reuters I/B/E/S.

Huaneng's strong profits contrasted with relatively anaemic results from some of its international peers, including Duke Energy Co in the United States and France's Edison. Many U.S. and European power producers have said they see no signs of a near-term rebound in demand..

Power demand tumbled in August 2008 when Beijing ordered the closure of many northern China factories in an effort to cut pollution ahead of the Beijing Olympics.

China also saw the worst summer power crunch in four years last year as coal-fired power plants, which produce nearly 80 percent of China's electricity, curbed production because of soaring coal costs and tight supplies.

Huaneng's shares fell 5.7 percent in the third quarter, compared to Datang, which lost 14 percent, and Huadian, which rose 2.5 percent.