Ethanol futures snapped a seven-day winning streak on concern Greece’s bailout negotiations will falter and slow fuel demand.

Futures followed crude oil and gasoline lower as Greece resisted calls from Germany for a European overseer to head its budget. Ethanol is blended with gasoline to augment supply as part of U.S. energy plans to reduce fossil fuel use.

“That’s the big financial sword of Damocles hanging over our market,” said Peyton Feltus, president of Randolph Risk Management Inc. in Dallas. “I’m very worried about this and so is the rest of the market.”

Denatured ethanol for February delivery fell 3.1 cents, or 1.4 percent, to $2.166 a gallon on the Chicago Board of Trade, the first decline since Jan. 18 and the steepest drop since Jan. 13. Prices have fallen 1.7 percent this month and are heading for the third monthly slump.

In cash market trading ethanol in the U.S. Gulf sank 5 cents, or 2.2 percent, to $2.22 a gallon and in Chicago the additive decreased 4.5 cents, or 2.1 percent, to $2.12, according to data compiled by Bloomberg.

Ethanol on the West Coast fell 3 cents, or 1.3 percent, to $2.245 a gallon and in New York the biofuel decreased 2.5 cents, or 1.1 percent, to $2.245.

Crude for March delivery fell 78 cents, or 0.8 percent, to settle at $98.78 a barrel on the New York Mercantile Exchange. Prices are down 5 cents this month.

Gasoline for February delivery fell 5.61 cents, or 1.9 percent, to $2.8707 a gallon in New York. The contract covers reformulated gasoline, which is made to be blended with ethanol before delivery to filling stations.