Thanks for your comment. I already read subpart D and my OPS manual. Of course, I'm talking about an ETOPs flight with ETP's and ETOPS enroute alternates.
The fact is that we use a 5% of contingency for ALL of our ETOPS flight plans. The question was about using a 3% of contingency for ETOPS flights instead. I did not found anything in JAR stating that you must use a 5% and not a 3% in that kind of flights.
I work for a spanish charter carrier (my nick's three letter ICAO code...)
Cheers