PARIS (Reuters) - Debt-burdened retailer Casino said on Tuesday group sales fell 5.3% in the third quarter, as weakness in its core French market outpaced robust growth in Brazil.

Consolidated group net sales fell 5.3% on a same-store basis in the third quarter to 4.562 billion euros ($4.83 billion), the retailer said in a statement.

Last week, Casino reported French retail sales fell 5.6% in the third quarter year on year on a same-store basis, reflecting an 18.6% fall in hypermarket sales and an 11.5% fall in supermarket sales.

It also slashed its 2023 earnings outlook for France, saying investment required to fund price cuts to boost customer traffic and volume in its supermarkets and hypermarkets would weigh on profit.

Casino announced this month the finalisation of a deal to avert bankruptcy through debt restructuring agreed with main creditors, led by Czech billionaire Daniel Kretinsky.

France's sixth-largest retailer is facing the consequences of years of debt-fuelled deals that, following recent loss in market share and revenue decline, have put it on the verge of bankruptcy.

At September-end, Casino's group net debt stood at 6.2 billion euros, of which 5.6 billion euros was in France and 600 million euros in Brazil.

($1 = 0.9436 euros)