Confirming David's comment!
Yes, we did use the Ariba Sourcing Platform to run events for Government Agencies in EUROPE.
(Assuming you are from Italy?)
If spend is above respective thresholds, you are publishing your inquiry on OJEU / TED.
First step is to answer question "IV 1.2" (an electronic auction will be used) appropriately.
In some cases we have prepared suppliers, that an electronic auction "may be used" and then your are still free to decide, if you want to use an auction or not.
In several cases we have also used pre-publication notices in order to save some time in the process.
Please feel free to reach out to me directly, if you would like to discuss more: Florian.Boehme@SourcingOnDemand.com
We have good knowledge concerning Europe.
Happy Sourcing and best regards, Florian