Complex sentence: He became an executive director of Harcourt Developments, a property company founded by Pat Doherty with interests throughout Ireland, Britain, the Caribbean and the U.S. He was responsible for marketing, and the job allowed him to continue his interest in the arts.
Split into simpler sentences: He became an executive director or Harcourt Developments, the property company founded by Pat Doherty. He has beeen responsible for marketing and the job allows him to continue his interest in the arts.