VIVHY Vivendi SE (PK)

By Inti Landauro

PARIS--French telecom company Iliad SA (ILD.FR) Tuesday said it will add a 4G super fast service to its low-cost "Free" mobile subscription, in a sign of the developments that are shaking up the country's telephony market.

Customers who have Iliad's low-cost package will gain access to its 4G mobile internet connection at no extra cost to their existing subscription, the company said in a Tuesday statement.

Iliad launched French mobile services for as little as two euros ($2.70) a month in January 2012, forcing its larger competitors--Orange SA (ORA.FR), Vivendi SA's (VIV.FR) SFR and Bouygues SA's (EN.FR) Bouygues Telecom--to slash prices repeatedly since then in order to keep up.

These larger operators had said they were counting on the 4G premium service to raise prices.

Write to Inti Landauro at inti.landauro@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires