is trying to stop the founders of Hecate Energy Group LLC from exiting the Chicago-based renewable power venture, in which the Spanish oil giant already has a 40% stake, according to an unsealed lawsuit.

Hecate's founders are suing Repsol's US renewables unit through an affiliate, seeking to enforce sections of a $213 million investment agreement in 2021 that allegedly gave them the right to demand a full buyout three years later. When they said they would exercise the option, Repsol stalled for time, then made unreasonable demands at the last minute, according to the court complaint.