* Q3 sales 10.684 bln euros vs estimates 10.56 bln euros
* France accelerates sales growth; Brazil, Thailand weigh
* Purchasing deal with Intermarche expanded, shares up 7 pct (recasts with CFO comments, shares, analyst)
By Dominique Vidalon
PARIS, Oct 15 (Reuters) - French retailer Casino's third-quarter sales beat market expectations and it said it was reaping the benefits of price cuts at its domestic business, which recorded its highest growth in more than four years.
The robust French performance helped counter weak consumer electronics demand in Brazil, its second-biggest market by revenue, and the effects of August bombings in Thailand. It was a rare piece of good news this year for Casino, where group profit fell 36 percent in the first half.
The company also announced an expansion of its joint purchasing deal with unlisted peer Intermarche to cover more products as it seeks to generate savings by buying in greater bulk.
It shares, which have fallen by about 30 percent in 2015, rose by as much as 9 percent on Thursday. They were up 7.03 percent at 1011 GMT.
Casino, which makes 55 percent of its sales in emerging markets and controls Brazilian retailer GPA, said third-quarter group sales were 10.684 billion euros ($12.3 billion).
That represented a fall of 0.5 percent, stripping out acquisitions, currency effects and excluding petrol, following a 0.4 percent decline in the second quarter - but nevertheless beat analysts' forecasts of 10.56 billion.
In France, Casino's top market and where it has been cutting prices since 2013, same-store sales rose 2.4 percent, the best performance since the second quarter of 2011, with customer traffic up 3.7 percent.
The French business - which accounts for more than 40 percent of group revenue - had reported an operating loss of 53 million euros in the first-half, weighed down by the cost of implementing the price cuts, notably at the Geant Casino hypermarkets and LeaderPrice discount stores.
Finance Chief Antoine Giscard d'Estaing said Casino was sticking to a forecast that profitability would improve in France in the second half of the year.
Market consensus for 2015 group earnings before interest and tax (EBIT) of 1.680-1.780 billion euros was "realistic", given weaker Latin America currencies, notably Brazil's Real, he said. That would compare with 2.23 billion euros in 2014.
With Casino's price cuts now largely completed, analysts focused on the expansion of the purchasing deal with Intermarche. "The ramp-up in expected synergies with Intermarche is one of the key drivers behind the rebound we expect in domestic earnings (from H1 2015 bottom) as price investments will no longer deteriorate profitability," said Raymond James analyst Cedric Lecasble.
$1 = 0.8708 euros Editing by Andrew Callus and Pravin Char