Complex sentence: He was finance director of Costain from 1992 to 1995, and CEO from 1995 to 1997, after which he was CEO of Jarvis, and then CEO of Dunlop Slazenger.
Split into simpler sentences: He was finance director of Costain from 1992 to 1995, and CEO from 1995 to 1997. Then CEO of Jarvis, and then CEO of Dunlop Slazenger.