FRANKFURT - Covestro said on Monday that it had agreed to negotiate with suitor Abu Dhabi National Oil Co (ADNOC) based on a takeover offer of 62 euros ($66.5) per share, after months of courtship by the Emirates' energy company.

Discussions, which had been described as open-ended before, would now take the form of "concrete negotiations" with Covestro providing confirmatory due diligence information, it said.

A spokesperson for ADNOC said it welcomed Covestro's decision: "We look forward to jointly working with Covestro to swiftly progress due diligence for this important transaction."

It has taken the two sides more than a year to advance to this stage. ADNOC's initial approach Covestro with an informal acquisition offer was reported in June 2023, but it wasn't until September last year that the German target entered into open-ended formal discussions.

($1 = 0.9324 euros) ($1 = 0.9325 euros)

(Reporting by Ludwig Burger, Editing by Friederike Heine)