UPDATE 2-U.S. sets final duties on Chinese solar panels

* U.S. says China was dumping solar products

* Panels with non-Chinese solar cells excluded

(Updates throughout with more detail)

By Doug Palmer

WASHINGTON, Oct 10 (Reuters) - The United States onWednesday set steep final duties on billions of dollars of solarenergy products from China, but turned down a request fromlawmakers and U.S. manufacturers to expand the scope of itsorder.

The Commerce Department said Chinese companies were"dumping" solar cells and panels in the United States at prices18.32 percent to 249.96 percent below fair value, although someindividual companies received lower anti-dumping duty rates thanin a preliminary decision earlier this year.

The department also set additional countervailing dutiesranging from 14.78 to 15.97 percent to combat Chinese governmentsubsidies, significantly higher than preliminary levels.

In a decision that disappointed U.S. producers and cheeredU.S. companies that install solar panels, the department turneddown pleas to expand the scope of its order to include Chinesepanels made with non-Chinese solar cells.

SolarWorld Americas , the driving force behind theU.S. case, fears that will encourage Chinese producers to simplymove cell production to nearby countries to avoid U.S. duties.

The United States imported about $3.1 billion worth of solarcells and panels from China in 2011, although that figurecontains some product not covered by the investigation.

The duty decision was expected to further strain tradeU.S.-China relations, following a congressional panel report onMonday urging American companies not to do business with twoChinese telecommunications companies because of securityconcerns.

The United States also has slapped preliminary duties onwind turbine towers from China and is expected to launch a newprobe next week into charges that imports of Chinese hardwoodplywood are unfairly priced and subsidized.

"We have the most squabbles with our biggest tradingpartners," said Scott Miller, a trade policy specialist with theCenter for Strategic and International Studies, explaining thesteady stream of U.S.-China trade spats.

Total U.S.-China trade surpassed $500 billion last year,with U.S. imports from China a record $399.4 billion and U.S.exports to China a record $104.0 billion.

In the solar sector, producers in the United States andEurope complain China's rapid expansion of solar panelmanufacturing has created massive oversupply, erasing profitsand sending company share prices into a tailspin.

SolarWorld's German parent has also been behind a charge inEurope for duties on Chinese solar panel imports.

China has warned the U.S. and European cases could damagetrade ties and cripple development of the global solar and cleanenergy sector. It has already struck back by launching aninvestigation into imports of solar-grade polysilicon from boththe United States and South Korea.

Chinese manufacturer Suntech Power Holdings onWednesday was hit with a final anti-dumping duty of 31.73percent and a countervailing duty of 14.78 percent. The finalanti-dumping duty rate was in line with its preliminary rate,but the final countervailing duty rate was increased from 2.90percent earlier.

Trina Solar received a final 18.32 percentanti-dumping duty and a 15.97 percent countervailing duty,compared to preliminary rates of 31 percent and 4.73 percent.

A separate U.S. government agency, the U.S. InternationalTrade Commission, must give its approval for the duties to takeforce, although importers have been required to post bonds orcash deposits based on the preliminary rates.

The ITC vote is set for November.

The Obama administration has heavily backed solar and otherrenewable energy since taking office, pledging about $16 bln for26 projects through its clean energy loan program.

Republican presidential challenger Mitt Romney hascriticized the support, saying the federal government should notbe in the business of picking winners and losers.

(Additional reporting by Nichola Groom in Los Angeles; Editingby Sandra Maler, David Brunnstrom and Bob Burgdorfer)

((doug.palmer@thomsonreuters.com)(202 898 8341))