Toyota Motor and two affiliates will divest at least 12.5% of supplier Aisin, the companies said, a $1 billion deal that fueled hopes the automaker could step up sales of its cross-shareholdings.

The other sellers are Denso and Toyota Industries, Aisin said Thursday. It would buy back some of its own shares on the open market, in a bid to soften the deal's impact on its stock price.

The sale price of the shares has yet to be determined, Aisin said. Reuters calculations based on its closing share price showed the deal was worth ¥177.5 billion ($1.11 billion).