Under the deal with Noble Drilling Asset Holding Corp. of the United States, STX Offshore will deliver the vessel used for deep water oil exploration by May 2012, it said in a regulatory filing.
STX Offshore has won deals valued at $5.05 billion so far this year to build 65 vessels, it said.
Shares of STX Offshore were trading at 13,550 won on the Seoul bourse as of 1:30 p.m., up 2.26 percent.