"Merging" rows output
I know this is old but maybe it will help someone. I have found two possibilities, both with certain downsides.


Views merge rows module
does exactly what you need in terms of displaying results, however it messes up views pagination because it only changes the display of the query. But if you don't need pagination it's the way to go. Edit: I wrote a patch for the Views merge rows module to address the pagination issue. It now works perfectly.
Views Aggregation with concat function patch - if patching is an option - do it, then enable aggregation under Advanced in the view. Next step is to click on aggregation settings under the right field (in your case the 'contact' field) and set it to 'group concat'. This will aggregate the company and contact field and summarize the contact data as you specified.


Whereas this should work for the majority of use cases both solutions don't work for mine, that's why I created a new question here. Kind regards.