The WTI and Brent contracts settled lower Tuesday after the release of a key European Union economic indicator supported a pessimistic outlook for global crude oil demand.

Light sweet crude oil for September delivery lost $1.23 to end the day at $86.65 a barrel while Brent slipped 44 cents to settle at $109.47 a barrel. Eurostat, the statistical arm of the EU, on Tuesday announced that gross domestic product throughout the bloc rose by only 0.2 percent in the second quarter. GDP growth during the first quarter was a more robust 0.8 percent; however, Eurostat pointed out that the latest second quarter figure beats that of the corresponding period in 2010 by 1.7 percent.

The WTI contract price fluctuated from $85.62 to $87.93 during Tuesday's session.

Front-month natural gas lost nine cents to settle at $3.93 per thousand cubic feet. Forecast models show milder temperatures from the Midwest to the Northeast through the remainder of this month, chilling cooling demand projections for the regions.

The September natural gas contract traded within a range from $3.90 to $4.04 Tuesday.

The price of a gallon of reformulated gasoline fell two cents to end the day at $2.85. September gasoline peaked at $2.87 and bottomed out at $2.83.