(Corrects to clarify Westinghouse's new ownership in fifth paragraph)

SHANGHAI, Oct 24 (Reuters) - A second Westinghouse AP1000 nuclear reactor on China's eastern coast is now ready to go into full commercial operation after a week-long trial run, the project's operator said late on Tuesday.

The State Power Investment Corp (SPIC) said in a notice posted on its website that the first unit of the Haiyang nuclear reactor project in Shandong province completed a 168-hour full-load test late on Monday evening. The reactor unit began construction in 2009 and was finally connected to the grid in August.

China gave the go-ahead to build four Westinghouse-designed AP1000 reactors in 2007. The first unit at Sanmen in Zhejiang province was originally scheduled to go into full operation in 2014, but the unproven "third-generation" technology has been beset by years of delays as a result of safety concerns and unanticipated design problems.

Unit 1 at Sanmen was finally declared ready to go into full commercial operation last month, making it the world's first AP1000 reactor to be completed.

Westinghouse, which was acquired by Brookfield Business Partners from Japan's Toshiba in August, hoped China would serve as a shop window for its AP1000 design, which boasts enhanced "passive" safety features as well as higher levels of generation capacity.

Westinghouse filed for bankruptcy last year after its nuclear projects in the United States were also hit by billions of dollars of cost overruns.

China also hoped that AP1000 technology would be at the centre of its own ambitious nuclear power plans after signing a technology transfer agreement in 2006.

But after a root-and-branch industrial safety review in the wake of Japan's Fukushima disaster in 2011, China's nuclear programme has slowed considerably, and it is now unlikely to meet its 2020 capacity targets.

(Reporting by David Stanway; Editing by Joseph Radford)