In company with somebody/something
Definition 1 of 1
Pro Tip 1/3Social Situations
Use it to imply a social or formal gathering, emphasizing the presence of others. 
The ambassador was seen in company with foreign dignitaries.
Pro Tip 2/3Visible Association
It suggests a visible or known association with the person or thing mentioned. 
He was often in company with renowned artists.
Pro Tip 3/3Mutual Involvement
Implies a mutual involvement or participation in an activity or event. 
They were in company with each other during the charity event.