Oil-field services company Halliburton Co. posted weaker quarterly earnings Monday as revenue in the company’s North America business slumped, but cost cuts and a better-than-expected outlook pushed shares higher. Companies like Halliburton that supply the energy industry with equipment face a challenge as U.S. shale drillers look to cut spending amid a production slowdown. Chief Executive Jeff Miller told analysts that the company will continue to cut costs in its North America business. …