PARIS (Reuters) - France's Orange (>> Orange) strengthened sales at home and in Spain in the third quarter, driving up operating profits as Stephane Richard campaigns for a third term as chief executive.

The telecoms operator, whose margins have suffered from the competition of rival Iliad (>> Iliad) in France over the last four years, has focussed investments on its network and bundled fix and mobile offers to lure customers.

This strategy contrasts with that of competitors such as Altice (>> Altice), which acquired sports rights and created new TV channels with the hope to increase sales and margins.

Orange's revenue rose for the second quarter in a row in France, its best third-quarter results since 2008, with a net addition of 320,000 mobile contract customers.

The pressure on prices in the mobile market was showing signs of improvement, said chief financial officer Ramon Fernandez.

"We're in a phase that seems to show that things are calming down," Fernandez told reporters.

The former monopoly also confirmed its full-year guidance for 2017, including a higher annual core operating profit.

Richard, who is seeking a third 4-year term as chief executive in spring of 2018, said he would lay out more details on the group's strategy on an investor day scheduled on Dec. 7.

Orange's quarterly adjusted earnings before interest, taxation, depreciation and amortisation (EBITDA) rose by 2.1 percent on a comparable basis to 3.62 billion euros ($4.28 billion).

New European Union rules on roaming costs on the continent cut 83 million from the group's adjusted EBITDA, Orange said. Excluding that impact, Orange's core operating profit would have risen by 4.7 percent over the period.

($1 = 0.8451 euros)

(Reporting by Mathieu Rosemain; Editing by Sudip Kar-Gupta)

By Mathieu Rosemain and Gwénaëlle Barzic

Stocks treated in this article : Orange, Iliad, Altice