The companies submitted their offer on June 20, according to a filing on the European Commission website on Thursday. The EU competition enforcer extended its deadline for a decision to Aug. 24, without providing details of the concessions.

Sources say the companies plan to divest assets in Europe and the United States where the deal is also under regulatory scrutiny.

Taiyo Nippon Sanso Corp and private equity firm Carlyle Group are the frontrunners to buy assets, sources told Reuters earlier this week. Securing a potential buyer could help allay regulatory worries.

(Reporting by Foo Yun Chee)