Oh, when I saw "academic", I thought you were speaking about their education ranks like Doctor, PhD, Master degree etc... 
You mean the military rank... 
Well in this link:
http://www.ambafrance-it.org/spip.php?article1513
You have the speech of the ambassador of France (I believe in Italy) when he gave the "médaille militaire" (military medal) to the "adjudant-chef Hubert Levent". Following google traduction, adjudant-chef is the equivalent of CWO (chief warrant officer).
And he starts his speech with:
	
	
		
		
			Il est rare qu’une Médaille militaire soit remise en ces lieux solennels. C’est peut-être la première fois.
      J’ai accepté de remettre la médaille militaire à l’Adjudant-Chef  Levent pour deux raisons. Tout d’abord en raison même de ses qualités  éminentes sur lesquelles je reviendrai, mais aussi parce que l’un de vos  aïeux, Edmond Le Blanc, a été le premier Directeur de l’Ecole française  de Rome de 1883. Son souvenir est conservé dans les archives  familiales.
		
		
	 
The part I highlighted means:
I accepted to deliver the military medal to the CWO Levent (his family name) for two reasons... etc...
So, he used this partern: [rank] [family name].  
Does it answer your question?
edit:
Later in his speech he says:
	
	
		
		
			Aujourd’hui c’est l’adjudant - chef Hubert Levent qui est honoré.
		
		
	 
it means:
Today, it's the CWO Hubert Levent who is honored..."
So, [Rank] then [first name] then [last/family name] 
So I think that there is no written rule... Just that we cant call him "sir Levent" or "Monsieur Levent", as his a military officer and we rather use his rank. 
And it's too familiar to use his name (first name)... So we use, out of respect, his last/family name.