I already suggested Kompass UKhave you researched similar sites? is it the most extensive?
I used to use paper Kompass directories when I was at work, and later used their online service via the Dialog host system. They offer a long-established and useful set of directories, usually one per country. We used industry-specific directories like the one produced annually by Polymers Paint Colour Journal
more often, but for general queries Kompass was our first call.
also the problem is I can't seem to find a way to filter results by country (I only need companies with UK presence)
I haven't used their free Web version, but, we're talking about Kompass UK
. Hence it will lists companies with a local UK presence, including UK subsidiaries of international companies.