Oil futures ended slightly lower Friday, paring losses but remaining in negative territory after data showed the number of U.S. oil rigs rose for a sixth straight week. September West Texas Intermediate crude futures fell 13 cents, or 0.3%, to end at $41.80 a barrel. For the week, the U.S. crude benchmark rose 0.5%.
Continue Reading Below
Copyright © 2016 MarketWatch, Inc.