Japan’s carmakers are putting the finishing touches on a combine-and-compete strategy for an automotive age defined by batteries and software, with three manufacturers joining forces to complement a separate Toyota-led coalition.

Honda and Nissan agreed this week to build upon a preliminary deal first reached in March, offering more details of how they plan to work together and also adding Mitsubishi Motors to the mix.

While the companies haven’t yet discussed a capital alliance, forming one is a possibility, Honda Chief Executive Officer Toshihiro Mibe said.