U.S. shale oil producer Pioneer Natural Resources Co. (NYSE: PXD) posted a 72% drop in quarterly profit Aug. 7, hurt by higher costs and a derivative loss of $170 million.

Net income fell to $66 million, or 38 cents per share, in the second quarter ended June 30, from $233 million, or $1.36 per share, a year ago.

The year-ago quarter included a gain of $195 million, mainly related to the sale of acreage in Texas.

Production rose to 327,704 barrels of oil equivalent per day (boe/d) from 259,087 boe/d in the quarter.