SWEDISH PRIME MINISTER'S CHINA VISIT BOOSTS TRADE An big expansion in bilateral trade is expected as a result of Swedish Prime Minister Ingvar Carlsson's visit to China, a official of China's Foreign Economic Relations and Trade Ministry official said. He told the China Daily that petroleum, coal, cotton, non-ferrous metals and electric engines could help balance the trade running at over three-to-one in Sweden's favour. Total trade reached 290 mln dlrs last year, up 32 pct on 1985, according to Chinese statistics. Swedish sources said major paper mill projects and an aviation agreement would be discussed during Carlsson's one week visit.