BOGOTÁ, Colombia, Sept. 1, 2021 /PRNewswire/ -- Ecopetrol S.A. (BVC: ECOPETROL; NYSE: EC) reports that the rating agency Moody's Investors Service ("Moody's") affirmed Ecopetrol's credit rating at Baa3 and changed its outlook from Stable to Negative. Moody's considers that the acquisition...