UK Filming Production directory
http://www.ukfilming.co.uk/

A list of independent production companies.
http://thetvroom.com/misc/links-01-70.html

One of the companies that stood out for me:
"MENTORN FILMS Mentorn Media's output has a breadth and quality that ranks it as one of the UK's foremost producers. Established in 1985, Mentorn Media is one of the UK's longest established independent television production companies, making thousands of hours for broadcasters in the UK and worldwide. Our offices in London, Oxford, Cardiff and Glasgow produce programmes across a range of genres."

Another list of independent production companies in the UK

http://www2.tv-ark.org.uk/Links/indies.html

I then googled "independent production companies based in the north east of england" and this came up:

North East missing out on TV and film production money

http://www.bbc.com/news/uk-england-26682499

High hopes eey

Anyway, here is a list of independent production companies in the North East (England)

http://www.yell.com/ucs/UcsSearchAction.do?keywords=production+companies&location=north+east+england&find=Y&pageNum=1

a few more: 

http://www.northernmedia.org/

NORTHERN FILM & MEDIA IS A SCREEN-BASED MEDIA AND CREATIVE DEVELOPMENT AGENCY COMMITTED TO DRIVING FILM, TV AND DIGITAL ARTS PROJECTS.

http://www.hungrywolfproductions.com/

Hungry Wolf Productions is a TV & film production company

http://www.danperryproductions.co.uk/index.php

Dan Perry Productions produces high quality content for film, television, documentary and corporate projects from pre-production through to filming and post-production.