He has been Choice's programme controller for 11 years and will still hold responsibility for all programming matters, but will also focus on the strategic direction of the station.
Etienne said: "I'm really looking forward to further developing Choice FM nationally, and in the London marketplace.
"I remain focused on delivering exciting programming initiatives, as well as strategic results for both the station and group as a whole."
Etienne is the first dedicated MD for Choice. Until his departure in November last year, Graham Bryce was managing director of Choice, Capital Gold and Xfm.
Bryce was not replaced and Nick Davidson was appointed MD of Xfm. He does not have an opposite number at Capital Gold. Both Davidson and Etienne report to Steve Orchard, operations director at GCap. Choice FM has a national weekly reach of 612,000.