Investing.com - European luxury goods companies could become casualties of a U.S.-China trade war.UBS says a full-blown trade war could cause double-digit damage to earnings and knock 30% off the shares of several luxury brands.In a note to clients, the firm says a worst-case scenario would create a negative wealth effect and weaken consumer confidence in the world's two largest economies.Together that would reduce consumer spending in the U.S. and China, which together account for 55% of all sales of luxury goods.UBS says Swatch of Switzerland, Burberry of the U.K. and Salvatore Ferragamo of Italy face the biggest potential hits.