[ns] queueing or queuing (for English people)

[salcaraz@obelix.umh.es]

Hi all, and sorry for the question:

How do you say:

Priority queueing
or
Priority queuing??

I have founded the above two sentences, with 'e' -> 'queueing' and without 
'e' -> 'queuing'

Thank you very much

/salva