Basically, none. If you fly in Europe for a Euro carrier, you have to have a JAA licence. It is possible to get a validation of an ICAO licence under JAA, but you may find the hours requirements a problem. Also, you can't put a type on a validated licence - so you would need the type rating on your ICAO licence. And finally, you would have to complete the requirements for a JAA licence within 12 months of arrival.
Having said that, we (and many others) are recruiting non-Euros and putting them through the grinder. Not 146 rated are you?
Of course, you will also need the right to live and work in the EU, or qualify under one of the greencard schemes.
PM me if you need more info.