The shares declined 6.9 percent to NT$167.5 by the 1:30 p.m. close on the Gretai Securities Market, Taiwan's second- biggest stock exchange. The benchmark TAIEX index fell 0.04 percent.

Taipei-based Motech's products turn sunlight into electricity. The company's sales have risen as governments in countries including Germany subsidize the cost of solar power use to cut greenhouse gas emissions, blamed for rising temperatures. The German government on Dec. 5 called for cuts to solar-power subsidies to help lower generation costs.

"Solar power is still dependent on government subsidies, and that may be cut during a global economic slowdown," said Terence Wu, an analyst at Yuanta Research Center in Taipei. "Investors are dumping solar energy stocks because of weak market sentiment."

Taiwan's government subsidizes as much as half of the cost of installing solar power systems.

December sales rose 33 percent from a year earlier, Motech said in a stock exchange filing Jan. 10. That was slower than 49 percent in the previous month.

Wu has a "buy" recommendation on the stock because "the valuation is reasonable," he said.

A U.S. retail report today may add to evidence that the world's biggest economy is on the brink of a recession, dampening global economic growth.

Retail sales in the U.S. fell 0.3 percent in January, following a 0.4 percent decline in December, according to the median forecast in a Bloomberg News survey of economists before the Commerce Department's report yesterday. The last time sales dropped for two straight months was in December 2001.