(Corrects launch date for China Hualong 1 reactor to 2020 in paragraph 8, not 2016)
BEIJING, March 9 (Reuters) - The world's first Westinghouse AP1000 nuclear reactor will go into operation in June next year, more than three years behind the original schedule, the head of China's leading state nuclear project developer said.
"We are forecasting that if everything goes smoothly, the first unit will go into operation in June 2017, and the second unit at the end of 2017," said Sun Qin, the chairman of the China National Nuclear Corporation, speaking to Reuters on the sidelines of the annual session of parliament.
"Construction has been delayed three years. At first we planned on December 2013 but there was just no way, with key pieces of equipment not available," he said.
The "third-generation" reactor, designed by the U.S.-based Westinghouse, has been plagued by delays brought about by design flaws and problems with key components. Sun said new coolant pumps for the two reactor units only arrived at the end of last year.
Westinghouse is a unit of Japan's Toshiba Corp.
A rival third-generation design, the European Pressurised Reactor (EPR), has faced similar problems, with projects in France, Finland and China all delayed.
But Sun said he was hopeful that China's own third-generation model, known as the Hualong 1, will progress more smoothly.
China's first Hualong 1 reactor unit, under construction at Fuqing in southeast China's Fujian province, is expected to be completed by around June 2020, he said.
China has also started construction on an identical Hualong 1 unit in Pakistan.
Reporting by David Stanway and Kathy Chen; Editing by Richard Pullin