Complex sentence: Dentsu Incorporated and their subsidiary, Japanese Public Television, contracted for the development of Venutia into a commercial cartoon enterprise working closely with the United Nations and their 1979 International Year of the Child.
Split into simpler sentences: Dentsu Incorporated and their subsidiary, Japanese Public Television, contracted for the development of Venutia into a commercial cartoon enteprise. Working with the United Nations and their 1979 International Year of the Child.