J,
For a Licence conversion through the UK CAA, Check out:
www.caa.co.uk/docs/175/srg_fcl_gid25.pdf
specifically: Part 5 on page 5, Note 2. Also do a search for licence conversions here in pprune.
But I think with your FAA Licence you should be able to apply for jobs with some operators. I'm not sure which ones. To apply for a job with an EU operator you must have the right to live and work in Europe.
Whereabouts were you thinking you'd like to fly?
Good Luck!