Vietnam, the world's second largest rice exporter, exported 1.8 million tons of rice worth 516 million U.S. dollars in the first five months of this year, posting respective year-on-year decreases of 14 percent and 4 percent, local newspaper Saigon Liberation reported Wednesday.

Freight charges surging up to about 30-35 percent of the export price, partly caused export of the local product down, the newspaper quoted Nguyen thi Nguyet, general secretary of Vietnam Food Association as saying.

Vietnam shipped over 4.7 million tons of rice worth 1.3 billion dollars last year. Its government has recently decided that the rice export volume should be within 4-4.5 million tons in this year to ensure food security.