WASHINGTON, March 20 (Reuters) - The Clinton administration will unveil Monday its plans to eliminate the controversial fuel additive MTBE in gasoline and promote the use of renewable additives like ethanol.

The administration's plans will be announced at a 1:30 p.m. (1830 GMT) news conference by U.S. Agriculture Secretary Dan Glickman and U.S. Environmental Protection Agency administrator Carol Browner.

The administration will announce a legislative framework for Congress to give the administration authority to quickly eliminate MTBE, a government official told Reuters.

As a backup plan, the EPA will begin the process of proposing new regulations to phase out the controversial fuel additive, the official said.

The timetable for the administration's plans to eliminate MTBE was not immediately known.

MTBE (methyl tertiary butyl ether), a possible human carcinogen, is used in about 85 percent of reformulated gasoline, which is required in parts of the country with the worst air pollution problems.

Ethanol, made primarily from corn, is the main competitor to MTBE in the fuel oxygen additive market.

Reformulated gasoline accounts for about 30 percent of the gasoline sold in the United States. Reformulated gasoline using MTBE has greatly reduced smog-forming gasoline emissions, but the additive has also contaminated water supplies in areas such as California and the Northeast, where reformulated gasoline is required.

The Energy Department has said phasing out MTBE would be equivalent to losing some 400,000 barrels per day of gasoline production. (--Tom Doggett, Washington Energy Desk, 202-898-8320)

High Plains Corporation is engaged in the production and sale of fuel grade and industrial grade ethanol. Fuel grade ethanol is the Company's primary product, while industrial grade ethanol represents a recent diversification. Fuel grade ethanol is sold for blending with gasoline as a motor fuel. In addition, the Company sells distiller's grains, both wet and dry, and other solubles. The primary by-product of ethanol production is distiller's grains.