Schlumberger Ltd. said its third-quarter earnings fell 49% as low commodities prices continued to pressure pricing and demand for its services from oil producers. “The business environment deteriorated further in the third quarter” Chief ExecutivePaal Kibsgaard said in prepared remarks Thursday. Shares edged down 0.7% to $75.60 in after-hours trading. They have fallen 15% in the past 12 months. For the latest quarter, Schlumberger reported that revenue in North America dropped 47%. For its operations outside North America, revenue fell 27%. Mr. Kibsgaard said previous cost-cutting initiatives and the company’s transformation program enabled Schlumberger to protect its financial performance “in what is shaping up to be the most severe downturn in the industry for decades.”