Toyota Motor and Matsushita Electric Industrial have strengthened their business ties by increasing their cross shareholdings.

A securities filing by Toyota on Monday revealed that the Japanese auto giant owned an 0.84% stake in the electronics group at the end of the last business year, 31 March.

It was not clear from the filing when the purchase was made or how much Toyota paid for the shares. The stake, however, was worth JPY49.16bn (US$398m) at the end of March.

Meanwhile, Matsushita owned 0.57% of Toyota on 31 March, 2006, Reuters said today. The news agency quoted a Matsushita spokesperson as saying the two companies “have been buying each others’ shares in chunks of tens of billions of yen.” He did not reveal further details, but said: “Toyota is our biggest business partner in the field of car electronics, and we are in the process of strengthening our ties.”

The two firms together own Panasonic EV Energy, a maker of batteries for Toyota’s hybrid vehicles.