The deal from an American customer calls for Daewoo Shipbuilding & Marine Engineering to deliver the vessels, used for deep-water oil exploration, by April 2011, the company said in a regulatory filing.
Shares of Daewoo Shipbuilding & Marine Engineering closed at 46,500 won on the Seoul bourse, down 2.92 percent.
Daewoo Shipbuilding & Marine Engineering has set this year's target for orders at $17.5 billion. The shipbuilder posted a net profit of 78.4 billion won in the first quarter, up 51 percent from a year earlier, on sales of 2.12 trillion won.