Under the deal with a major oil firm, Daewoo Shipbuilding will deliver the hull of the platform by December 2012, the company said.
Daewoo Shipbuilding did not reveal the name of the buyer.
So far, Daewoo Shipbuilding has won deals valued at around $ 5.8 billion to build nine offshore platform facilities and a floating production, storage and offloading (FPSO) vessel.
Shares of Daewoo Shipbuilding were trading at 28,550 won on the Seoul bourse as of 10:55 a.m., up 2.7 percent.