The production line at a Panasonic factory in Tokushima prefecture will have enough capacity to build batteries for around 500,000 vehicles a year, Prime Planet Energy & Solutions, Inc said in a statement.

"The global electric vehicle market is expected to continue growing rapidly," the company said.

Established in April, Prime Planet Energy is 51% owned by Toyota Motor with Panasonic holding the remaining stake. The venture reflects the drive of both companies to become bigger global players in an industry vital for the development of affordable EVs.

Panasonic, one of the world's biggest EV battery makers, faces intense competition as a battery supplier to global automakers, including Tesla Inc. The other leading players are South Korean and Chinese makers such as Samsung SDI Co, LG Chem and CATL.

Toyota, Japan's biggest carmaker, last month said it expects annual sales of EV vehicles to reach 5.5 million in 2025, five years earlier than initially planned.

(Reporting by Tim Kelly; Editing by Muralikumar Anantharaman and Sherry Jacob-Phillips)