“ The Office of Personnel Management is hereby authorized and designated, pursuant to section 5305 (a) of title 5, United States Code, as amended by section 101 of FEPCA, to exercise the authorities of the President under section 5305 of title 5, United States Code, concerning higher rates of pay. (b) Before exercising the delegated authorities under subsection (a) regarding employees in positions other than those covered by the General Schedule, the Office of Personnel Management shall consult with the head of the agency employing such employees. ”