Nov 9 (Reuters) - U.S. ethanol trade groups will petition U.S. Trade Representative Robert Lighthizer to remove Brazil’s designated country status under the Generalized System of Preferences in response to Brazil imposing a tariff and quota on imports of U.S. ethanol, according to a letter seen by Reuters on Thursday.
* Letter says 20 percent tariff on Brazil imports of U.S. ethanol that surpass the quota of 158.5 million gallons make Brazil no longer eligible for GSP status, which exempts the country from some World Trade Organization rules
* Brazil imported 500 million gallons of U.S. ethanol in 2016/17 marketing season, making country largest market for U.S. exports
* Letter signed by Renewable Fuels Association, Growth Energy and the U.S. Grains Council
Reporting by Michael Hirtzer in Chicago