FACTBOX-Top S&P 500 companies exposed to China

March 21 (Reuters) - Investor worries about a trade warbetween the United States and China ratcheted up on Wednesday,leaving a number of large U.S. companies potentially in thecrosshairs of a dispute because of their business with China. The tariffs on steel and aluminum imports proposed on March1 and signed into law by U.S. President Donald Trump on March 8have sparked concerns of a global trade war and frayedinvestors' nerves. Trump will likely announce tariffs on Chinese imports byFriday, a source in the administration said, as the top U.S.trade diplomat told lawmakers he had the tools to strike backover Chinese theft of U.S. technology know-how. A report in the Wall Street Journal said China was planningcounter-measures against U.S. tariffs. Among the most affected could be the technology sector,particularly semiconductor companies, which have high revenueexposure to China, according to UBS. Shares of U.S. exporters of agricultural products such assoybeans and meat slipped on Wednesday. The Journal report saidChina was preparing tariffs targeted at U.S. agricultureexports. Other business areas with companies that have high revenueexposure include the life-science tool industry and the consumerdiscretionary sector. The following are the S&P 500 companies with the highestrevenue exposure to China, according to UBS and FactSet data, aswell as U.S. industries with the biggest imports from andexports to China: S&P 500 company Revenue from Share performance China (est.) since Feb. 28 Skyworks Solutions 80.0 pct -0.7 pct Qualcomm 63.3 pct -14.4 pct Qorvo 60.0 pct -8.8 pct Broadcom 51.9 pct -0.2 pct Micron Technology 49.5 pct 20.1 pct Texas Instruments 42.9 pct 0.3 pct A.O. Smith 33.4 pct 2.2 pct Microchip Technology 31.0 pct 10.4 pct Amphenol 28.6 pct -0.4 pct Expeditors International 26.5 pct -1.4 pct of Washington Source: FactSet and UBS Top importers from China 2017 imports (blns of $) Communications Equipment $78.0 Computer Equipment $58.6 Misc. Manufactured $36.5 Commodities Apparel $24.6 Semiconductors $23.2 Top exporters to China 2017 exports (blns of $) Aerospace Products and $16.3 Parts Agricultural Products $15.9 Motor Vehicles $10.1 Semiconductors $6.9 Oil & Gas $6.9 Imports/exports data source: U.S. Census Bureau, Haver, UBS (Reporting by Lewis Krauskopf, April Joyner and CarolineValetkevitch; Editing by Peter Cooney)