The offer, which CTG says represents a 10% premium on EDP shares’ six-month volume-weighted average price, values EDP at over €11.8 billion.
CTG simultaneously published a €7.33/share offer for the 82.6% stake EDP has in its renewables subsidiary, EDP Renováveis.
Communicating the offer to the Portuguese stockmarket regulator CMVM, CTG promised EDP would remain "an important strategic asset with Portuguese identity, listed on the Euronext Lisbon and with headquarters in Lisbon while retaining a high level of autonomy".
According to the Expresso newspaper, CTG has been talking to the Portuguese government about buying out EDP since rumours emerged last year about a possible merger between EDP and the Spanish energy company Gas Natural.
On 9 May, EDPR reported a 39% growth in net profit for Q1 2018.