By Chris Prentice, Reuters.

U.S. environmental regulators have denied a request from oil refiners to waive some of their advanced biofuels use requirements from 2016, in what is likely to be one of the Obama administration's final decisions on the controversial program.

The denial, published on Environmental Protection Agency's website on Wednesday, comes just days before President-elect Donald Trump takes office and as his nominee for EPA chief was being questioned in a Senate hearing.

The Renewable Fuel Standard (RFS) program was signed into law in 2005 and designed to boost a renewable fuel industry annually. It requires oil companies to use increasing volumes of biofuels including cellulosic ethanol, which is produced of plant waste material.

AFPM and others from the oil industry have spent years lobbying EPA to lower the biofuels requirements, saying they are unachievable.

The EPA in a Jan. 17 letter to the American Fuel and Petrochemical Manufacturers (AFPM) said it was denying the group's request to waive some of the volumes that previously the agency said would be required for use in 2016, citing short supplies.