ConocoPhillips split into two major energy firms Tuesday, abandoning the super-major model that its retiring leader helped engineer a decade ago. After directing the 2002 merger of Conoco and Phillips Petroleum CEO James Mulva’s final act was to disassemble it. He leaves behind a more modest oil E&P company, streamlined by the aggressive asset sell-off that has defined his final years at the helm. Meanwhile, the refineries, chemicals and pipelines that helped ConocoPhillips to be the third largest corporation have spun off into a new company, Phillips66. Both firms are headquartered in Houston.