Oil prices fell on Friday as a rising U.S. rig count stoked fears of global oversupply and after Chinese regulators opened an investigation into suspected stock market manipulation. U.S. oil drilling increased this week for the first time after 29 weeks of declines, a sign U.S. oil production may start to increase more strongly again after a slowdown due to a period of low oil prices. Oil rigs increased by 12 to 640 following a slump that cut the number of active U.S. rigs from a peak of 1,609 in October to a nearly five-year low last week, energy services firm Baker Hughes Inc ( BHI.N ) said. “This is the first weekly increase in 30 weeks and is an indication that the slump in drilling activity has ended,” said Carsten Fritsch, senior oil analyst at Commerzbank in Frankfurt. “Oil prices have retreated on that news,” Fritsch told […]