South Korea's Hyundai Motor Co and KIA Motors Corp have sharply cut vehicle production in China، sources said، as anti-Korean sentiment and competition from Chinese brands play havoc on sales and threaten earnings. Reuters reported. Hyundai and Kia saw their combined China sales slump by 52 percent in March from a year earlier، another person said، endangering not only the automakers' earnings but those of its South Korean suppliers. China، the world's biggest auto market، accounted for over a quarter of the pair's 2016 overseas sales. A Chinese backlash over the deployment of a U.S. missile defense system outside Seoul has targeted South Korean firms including Lotte Group with boycott calls in state media، protests and suspensions of operations. The move angered Beijing، although Seoul says the system is a response to North Korea's nuclear threat and is not aimed at China. While the diplomatic row is a nuisance، the bigger problem for the South Korean carmakers is stiff competition in China and the United States، where their mainstay sedans have lost market share to sport utility vehicles، analysts and sources said.