The U.S. Environmental Protection Agency granted oil major Exxon Mobil Corp ( XOM.N ) a financial hardship waiver this year temporarily freeing its Montana refinery from U.S. biofuel laws, three sources familiar with the matter told Reuters. Exxon, which reported earnings of almost $20 billion in 2017, became the largest known company to be awarded a such a waiver by the Trump administration’s EPA under a program meant to protect the smallest fuel facilities from going bust. Farm-state lawmakers have complained that the hardship waivers are being overused in a way that is killing demand for corn-based ethanol, and they were likely to criticize the waiver awarded […]