Cambodia Iron and Steel Mining Industry Group and China Railway Major Bridge Engineering Group signed a Memorandum of Understanding on Monday to build a railway and a seaport in Cambodia, Xinhua News Agency reported.

The two firms will jointly build a 404-kilometer railway from Preah Vihear province to Koh Kong province and a seaport in Koh Kong province to support the metal mining industry in Preah Vihear province.

Reuters reported that the railway and the seaport will cost $9.6 billion, and that the two companies will also build a steel plant with an investment of $1.6 billion.

The three projects will start construction this year and take four years to complete.

Meanwhile, Sinomach China Perfect Machinery Industry Corp won approval from Cambodia's oil and gas regulator on Dec 27 to jointly invest $2.3 billion with Cambodian Petrochemical Co in an oil refinery in the southwest of the country, which will be the country's first oil refinery, AFP reported.