The contract is for 15 years beginning in April 2010.
Petronas said in a statement the sale and purchase agreement was signed in Kuala Lumpur by MLNG Chairman Hassan Marican and Momoki Tokiwa, President of Shikoku Electric.
The deal carries an option to extend it for another five years, the statement added.
Shikoku Electric, like the island it serves, is one of 10 regional electric utilities licensed by the Japanese government to generate, transmit, and distribute power.
Shikoku (known as Yonden in Japan) provides electricity to more than 4 million people in the four prefectures of Shikoku.
The LNG will be transported from the Petronas LNG complex in Bintulu, Sarawak, to Shikoku Electric's new receiving terminal in Sakaide, Japan, on LNG tankers owned and operated by MISC, the shipping subsidiary of Petronas.The receiving terminal, currently under construction and due for completion in 2010, is owned by Sakaide LNG Co Inc, a joint venture between Shikoku Electric, Cosmo Oil Co Ltd and Shikoku Gas Co Ltd.