Ethanol production in the United States decreased 4 percent to 859,000 barrels a day last year, or 13.2 billion gallons on an annualized basis, down from 13.8 billion gallons in 2011 according to Bloomberg News calculations based on an Energy Department report last week. Stockpiles fell to 20.2 million barrels in the 7 days ending December 28, 2012 from 20.3 million from the previous week.

The decline in ethanol output in 2012 is the first decrease in 16 years.  Bloomberg said the lower production was the result of corn prices “crimping” profit margins. Imports of ethanol last week increased to 87,000 barrels a day from 26,000 the previous week, the department said. Ethanol-blended gasoline made up about 87 percent of the total U.S. gasoline pool, down from 89 percent in the week ending December 21 and the lowest since January 6, 2012.