MEXICO CITY, April 30 (Reuters) - The net contribution of Mexican state-owned oil firm Pemex to Mexico’s government coffers will be zero in the future, Moody’s analyst Ariane Ortiz-Bollin forecast on Friday. Owing to a drop in oil prices and Pemex crude production “the net contribution to the fiscal coffers will be zero” because the government will be contributing around one percentage point of GDP in support to Pemex, while Pemex will now be contributing to the government about one percentage point of GDP in revenues, said Ortiz-Bollin. “That is what we are taking into account, zero in net terms of Pemex’s contribution to the sovereign,” she said. (Reporting by Sharay Angulo)