A former Toyota Motor Corp. executive is telling the carmaker's second-biggest supplier to raise its game across its auto parts businesses or risk being benched.

Yasumori Ihara, who ran Toyota's emerging markets operations before becoming Aisin Seiki Co.'s president in June, plans to decide by the end of the year on ways to better organize the company and its nearly 180 subsidiaries, which make everything from car seats, transmissions and brakes to body parts.

Toyota and other Japanese automakers are putting pressure on their suppliers to become more competitive and avoid complacency resulting from the cosy "keiretsu" system, in which companies form interlocking business relationships through cross-shareholdings. As the nation's auto market shrinks and its carmakers expand overseas, they are forming relationships with local suppliers in those regions and urging their suppliers to do the same.