SEOUL (Reuters) - Hyundai Heavy Industries <009540.KS>, the world's largest shipbuilder, has won three orders worth a total $600 million to build oil and gas rigs.

Hyundai said in a statement it had won a $400 million order for a 35,000-tonne offshore oil platform scheduled to be delivered by August 2015. It did not identify the oil major which placed the order.

The other two orders are each worth $100 million.

One is to build a semi-submersible drilling rig for LLOG of the United States, which has an option exercisable to order an additional structure.

The other is for six "land plant modules" capable of producing 200 million cubic feet of natural gas and 10,000 barrels of oil a day for an unnamed U.S. oil major, with scheduled delivery in June 2015.

(Reporting by Sung-won Shim; Editing by Nick Macfie)