HOUSTON, Aug. 31 (Xinhua) -- The number of active drilling rigs in the United States increased by four to 1048 this week, showed weekly data released by Baker Hughes on Friday.

The Houston-based oilfield services company reported that the U.S. state of Mississippi led the gain with increasing by three rigs, while Texas remained level at 528.

The number of rigs operating in U.S. oil fields gained two to a total of 862 rigs this week, and more than half of the oil rigs were located in the Permian Basin region of western Texas and southeastern New Mexico. The number of rigs drilling for gas also gained two to a total of 184 rigs this week. The count of miscellaneous rigs remained level at two.

Oil prices retreated on Friday as U.S. energy companies added oil rigs for the first time in three weeks.

The West Texas Intermediate (WTI) for October delivery fell 0.45 U.S. dollar to settle at 69.80 dollars a barrel on the New York Mercantile Exchange, while Brent crude for October delivery lost 0.35 dollar to 77.42 dollars a barrel on the London ICE Futures Exchange.