co- BrE AmE ¦kəʊ AmE \ ¦koʊ —New compounds in co- vary between early and late stress, with a preference for late ( ˌ co-ar ˈ ranger) except when the second element has only one syllable ( ˈ co-heir). In established words, note however ˈ co ˌ pilot, ˈ cosine.
Meaning of CO- in English
Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012