Oil and gas traders are likely to seek waivers from Beijing over tariffs that the Chinese government plans to impose on U.S. crude and liquefied natural gas (LNG) imports from February 10, trade sources said on Thursday.Shortly after tariffs on China imposed by U.S. President Donald Trump took effect on Tuesday, China's Finance Ministry said it would impose levies of 15% on imports of U.S. coal and LNG and 10% for crude oil as well as on farm equipment and some autos, starting on February 10.Four tankers, carrying 6 million barrels of U.S.