Over a certain threshold (about £110,000 last time I was involved in one) contracts using public finances have to be advertised in the European Journal -
http://www.ojec.com/
It's a nightmare process, often a waste of time and money - in my job, if I had funding to buy a particular scientific instrument and knew after months or years of research that there was only one manufacturer world-wide that could supply it, I still had to go through the process of advertising and then go through arguments with accountants and auditors to justify rejecting the cheaper tenders that didn't meet the specs but they thought I should have just because they were cheapest.
