Dutch firm Guanabara Holdings is considering an offer for Irish carbon credit company EcoSecurities at a price of 60p per ordinary share.Guanabara is a company chaired by Dr Pedro Moura Costa, a founder of EcoSecurities. It is owned by Grandal Services, a company owned by Moura Costa's Mayanna Trust and BTG Carbon Luxembourg."BTG and Grandal have come together to form Guanabara for the specific purpose of jointly making a potential offer for EcoSecurities, said GuanabaraA further announcement is expected to be made by Guanabara in due course.