Shares of Neptune Orient Lines Ltd (NOL), the world's sixth largest container shipper, sank as much as 2.5 percent on Thursday morning to their lowest level since March 2000 on freight rate concerns. By the midday break, NOL had crawled back to S$1.20, down one cent, from S$1.18 in moderate trade of 2.78 million shares. Analysts said there were increased worries for its earnings due to prolonged pressure in freight rates with no short-term recovery in sight for cargo demand due to slowing economies. "People are concerned over pressures in freight rates," said Albert Goh, an analyst at Kim Eng Securities. NOL scrapped a planned share flotation and U.S. listing of its oil transportation unit last month.