* Q3 net profit 126.3 million euros, vs 108 million forecast
* Sales down 7.8 percent to 1.393 billion euros
* OTE says negative conditions to continue in last quarter
(Adds CEO comment, detail)
ATHENS, Nov 4 (Reuters) - Greek group OTE, the biggest telecoms company in southeast Europe, posted a 24 percent fall in third-quarter profit, showing the impact of increased competition in its austerity-hit markets.
Net profit fell to 126 million euros ($179 million), beating a 108 million forecast in a Reuters poll.
Sales declined 7.8 percent to 1.39 billion euros, as customers deserted the company for cheaper competitors.
Greece's former state monopoly, now 30-percent owned by Deutsche Telekom, kept its negative outlook as Greece struggles with the fallout from its debt crisis.
"OTE management estimates that the negative conditions that affected earnings and profitability in the nine months will continue in the final quarter of 2010," the company said. (Reporting by Harry Papachristou; Editing by Dan Lalor)