(Bloomberg) — Daewoo Shipbuilding & Marine Engineering Co., the world's third-largest shipbuilder, received a combined 1.44 trillion won ($1.37 billion) order from the U.S. for two drill ships as rising oil prices spur exploration.

The vessels, to be used for drilling in deep water, will be delivered by April 15, 2011, the Seoul-based company said in a regulatory filing, without identifying the buyer.

Record oil prices and depletion of reserves in shallower water are prompting companies such as Exxon Mobil Corp. and Royal Dutch Shell Plc to spend a record $98.7 billion this year on exploration and production, more than four times their investment eight years ago.

Petroleo Brasileiro SA, owner of the western hemisphere's largest oil discovery in three decades, plans to order 40 drilling ships and semi-submersibles worth about $30 billion for delivery by 2017.

With the order, Daewoo Shipbuilding has about $4.9 billion worth of contracts this year and a backlog of $40.8 billion that may take almost four years to clear.

Daewoo Shipbuilding dropped 2.9 percent to 46,500 won in Seoul.

The stock has fallen 9.9 percent this year, compared with a 3.7 percent decline in South Korea's benchmark Kospi index.