MEXICO CITY, Aug 30 (Reuters) - Mexican state oil firm Petroleos Mexicanos (Pemex) said on Monday that its has resumed 421,000 barrels per day in oil production and brought back online 125 wells following a deadly fire at an offshore platform on Aug. 22. The accident in the southern Gulf of Mexico at the offshore platform that is part of Pemex’s most productive oil field Ku-Maloob-Zaap, knocked out about 25% of Mexico’s total production. Reporting by Anthony Esposito Our Standards: The Thomson Reuters Trust Principles.