By Nick Kostov 

PARIS-- Orange SA's sales growth picked up slightly in the third quarter but a drop in revenue in its home market of France weighed on results.

Sales rose 0.4% to EUR10.32 billion ($11.23 billion) in the three months to Sept. 30, France's biggest phone carrier said Tuesday. That helped push up third-quarter earnings before interest, taxes, depreciation and amortization, or Ebitda, by 1% to EUR3.6 billion.

Analysts had expected sales of EUR10.27 billion and core earnings of EUR3.58 billion.

Having failed to buy Bouygues Telecom, Orange is now stuck competing with three rivals in the French market where a 4G mobile phone plan is available for less than EUR20 a month. Orange is betting it can beat out rivals by focusing on the quality of its network and services rather than lowering prices.

Orange's revenue in France fell 0.5% to EUR4.77 billion in the three months, hit by declining sales from mobile services. In its domestic market, the company added 134,000 domestic fixed broadband customers in the quarter and 187,000 net new mobile contracts.

Orange confirmed its full-year target of posting higher Ebitda in 2016 than in 2015 on a comparable basis. It also said it plans to propose a dividend of EUR0.60 a share.

Write to Nick Kostov at Nick.Kostov@wsj.com