The number of rigs drilling for oil in the U.S. rose by seven in the past week to 381, the sixth straight week of increases, according to oil-field services company Baker Hughes Inc. BHI 0.51 % The U.S. oil-rig count is typically viewed as a proxy for activity in the sector. After peaking at 1,609 in October 2014, low oil prices put downward pressure on production and the rig count fell sharply. The nation’s gas-rig count fell by five in the past week to 81. The U.S. offshore-rig count slipped by two rigs from last week at 17, which is 21 fewer than a year ago. Oil prices entered a bear market —marked by a decline of 20% from a recent peak—earlier this week, with U.S. futures dipping to a three-month low below $40 […]