DUBAI, Dec 8 (Reuters) - An affiliate of Saudi International Petrochemical Co 2310.SE (Sipchem) signed a contract with South Korea's eTEC E&C 016250.KQ for work costing 542.6 million riyals ($144.6 million) to raise the efficiency of operations at its methanol plant in Jubail.

International Methanol Co (IMC) is 65-percent owned by Sipchem, and a group of Japanese companies hold the rest, according to the bourse filing from Sipchem on Thursday.

The project is expected to be completed in the fourth quarter of 2018.

Under the contract, eTec will be in charge of doing engineering, procurement and construction work for efficiency enhancement. Sipchem did not give further details but said this project is part of efforts to meet targets for the Saudi Energy Efficiency Center.

It has an annual production capacity of 967,000 tonnes of methanol, according to Sipchem's website.

(Reporting by Reem Shamseddine; Editing by David French) ((Hadeel.AlSayegh@thomsonreuters.com; +971566883310;))