NEW YORK, July 30 (UPI) -- Crude oil prices continued a see-saw week, closing near $79 per barrel on the New York Mercantile Exchange.

Crude oil prices climbed sharply off a morning low of $76.83 to $78.98 per barrel, despite disappointing gross domestic product data.

The U.S. Bureau of Economic Analysis said Friday the GDP in the second quarter grew 2.4 percent, slightly less than expected, but confirming a general slowdown in economic growth. In the previous quarter, the GDP grew 2.7 percent.

August contract No. 2 heating oil prices gained 0.0146 cents from a prior settlement to $2.0518 per gallon. Reformulated blendstock gasoline for August delivery added 0.0228 cents to $2.1202 per gallon.

Henry Hub natural gas prices for September fell 0.075 cents to $4.902 per million British thermal units.

At the pump, the national average price for a gallon of unleaded gasoline was $2.741 Friday, off 0.003 cents from Thursday's $2.744 per gallon, AAA said.