Dutch firm Guanabara's 77p per share cash offer for Irish carbon credit company EcoSecurities has been rejected.EcoSecurities said it rejected the offer because it is "wholly inadequate", adding that it will issue a formal response on or before 5 August."In the meantime, EcoSecurities shareholders are strongly urged to take no action in relation to the Offer," it said. Guanabara said the offer price represents a significant premium of 69.2% to the closing price of 45.5p per share on 4 June 2009, being the last business day prior to the date of the announcement by Guanabara that it was considering an offer.The group reiterated that the offer provides shareholders with the certainty of a cash exit at a significant premium "in contrast to the considerable uncertainties that continue to overshadow the carbon credit aggregators and carbon trading markets, both during this current phase and after 2012."