The United States hit Chinese solar companies with anti-dumping tariffs of about 31 percent last week, further denting the outlook for an industry grappling with falling margins, oversupply and subsidy cuts in top European markets.

The U.S. ruling stems from a complaint filed last October by the U.S. subsidiary of Germany's SolarWorld AG, and six other U.S. companies that alleged unfair competition and had sought duties well above 100 percent.

Anti-dumping tariffs by Europe, which accounts for 70 percent of sales for Chinese solar companies, "would have a lethal impact on China's solar industry," Suntech Chairman and Chief Executive Zhengrong Shi told Reuters in an interview in Shanghai on Thursday.

The United States accounted for 34 percent of Suntech's sales in the first quarter, while Europe remained the New York-listed company's biggest market with a 44 percent share of revenue.

SolarWorld has said the momentum for trade complaints is building in the European Union against Chinese solar panel makers.

"European companies are preparing themselves for a trade case, anti-subsidy and anti-dumping, against China and Chinese companies," Milan Nitzsche, vice president of SolarWorld, told Reuters in Brussels on Tuesday.

"We just want to create a level playing field," Nitzsche said, without disclosing a time frame for a case.

Analysts warn European tariffs against Chinese solar companies would have serious consequences.

"That could be the death of the many Chinese solar companies," said CIMB Research analyst Keith Li.

"The costs of solar developers in Europe will rise and will only slow solar development and are unlikely to solve Europe's (solar producers') problems," he said.

German solar power equipment company Q-Cells filed for insolvency in April, becoming the most prominent victim so far in an industry shake-out sparked by plunging product prices amid massive overcapacity.

"There are signs that Europe is making some moves, and also India. We have noticed that, and have made preparations for that," said Miao Liansheng, chairman and CEO of Yingli Green Energy, one of China's largest solar equipment makers.

Yingli, whose shares have fallen nearly 75 percent in New York in the past year, will announce its first-quarter results on May 30.

Suntech and Trina Solar Ltd reported on Wednesday losses for the first quarter after posting profits a year earlier.

Suntech said on Thursday it saw little impact on its business from the U.S. anti-dumping duties and maintained its full-year guidance on shipments.

"The U.S. ruling was disappointing but expected," said Suntech's Shi.

Analysts say Chinese solar companies may circumvent the U.S. duties by moving some of their factories out of China.

At the close in New York on Wednesday, shares in Suntech and Yingli rose 2 percent, while Trina Solar gained 4 percent.

(Writing by Leonora Walet and Kazunori Takada; Additional Reporting by David Lin in Shanghai and Barbara.hm Lewis in Brussels.; Editing by Ryan Woo)

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