GS Yuasa's Thai unit Siam GS Battery (SGS) is buying 40% of joint venture Yuasa Battery Malaysia (YBML).

The agreement takes the group's stake to 70% giving YBML management rights to the group, and making it a consolidated subsidiary of GS Yuasa.

Yuasa has made lead-acid storage batteries for automobiles and motorcycles in Malaysia since 1979.

Competition has increased due to acquisitions and new entries but the group aims to expand market share through SGS which has 50 years' experience making and selling batteries in Thailand. The group's curent battery business has about 10% market share in Malaysia but plans to double sales by 2018.