* Sells 12 mln to 24 mln bbls diesel, 12 mln to 20 mln bbls naphtha

* Shipments set for Jan 1 to Dec 31 this year

(Adds details)

By Meeyoung Cho

SEOUL, Jan 27 (Reuters) - South Korea's S-Oil Corp said on Wednesday it had agreed to sell 1.34 trillion Korean won ($1.12 billion) of oil products to the trading arm of top shareholder Saudi Aramco, higher than sales of 1.2 trillion won contracted a year earlier.

The contract provides for the country's third-largest refiner to supply 12 million to 24 million barrels of diesel and 12 million to 20 million barrels of naphtha to Saudi Aramco Products Trading Company, S-Oil said in a filing to the stock exchange.

The shipments started from Jan. 1 this year and will run until Dec. 31, the refiner said, adding that the diesel would be ultra-low-sulphur and low-sulphur, while naphtha would be light naphtha.

Saudi Aramco is the top shareholder of S-Oil, which buys almost all its crude from Aramco. Saudi Aramco Products Trading Company is Aramco's trading arm.

In February 2015, S-Oil told the stock exchange it would supply up to 14 million barrels of diesel and up to 14 million barrels of light naphtha to Saudi Aramco Products Trading Co under a contract from Feb. 1 to Dec. 31 last year. ($1=1,200.24 won)

(Reporting by Meeyoung Cho; Additional reporting by Rebecca Jang; Editing by Clarence Fernandez) ((meeyoung.cho@thomsonreuters.com; +82 2 3704 5653; Reuters Messaging: meeyoung.cho.reuters.com@reuters.net))

Keywords: SOUTHKOREA SOIL/