A.P. Moller-Maersk spokesman Michael Storgaard says Eivind Kolding has told Bloomberg: "We will have a substantial loss this year and next year will be equally difficult."
Maersk Line is the world's biggest container shipping firm.
"It's the news Maersk Line will lose money in 2009 and 2010 and the lower container ship volumes, which Eivind Kolding is quoted on (that moves the share)", says Mads Zink, chief trader at Danske Bank.
A.P. Moller-Maersk swung to its first group loss since World War Two in the first quarter amid slowing global trade, and warned the full year might end in deficit too.