SOUTH KOREA INCREASES DUTY ON CRUDE IMPORTS South Korea has increased its duty on crude oil imports to 4.29 dlrs a barrel from 3.29 dlrs, effective today, the energy ministry said. The duty, to raise funds for special energy projects, was adjusted after average crude import prices rose to 16.85 dlrs a barrel in April, from 16.65 dlrs in March and 13.08 dlrs in April 1986, ministry officials said. A separate 24.5 pct import tax on crude oil is unchanged.