Casino, which also operates under the Monoprix, Leader and Geant banners, said Q1 consolidated sales hit €5.94bn (£4.1bn), up from last year's €5bn and beating analyst predictions of €5.8bn.
Domestic sales rose 3.4 per cent, as price cuts and improved value for money on private label goods boosted the firm's competitiveness in the tough French grocery sector.
Own-label products enjoyed double-digit volume growth in Casino's hypermarket format, as the continuing deflationary trend boosted sales.
But overall, sales in the hypermarket formula grew only 1.3 per cent to €1.44bn, compared to 2005's €1.42bn.
The Casino and Monoprix convenience formats generated a 3.1 per cent sales rise, as demand for smaller stores and later opening hours increases.
During the quarter the firm opened 79,000 square metres of retail space in France, which Casino claims "attests to the momentum and attractiveness of the Group's banners, [and] will increase the pace of organic growth in coming quarters."
For 2006, the firm has a target of opening 170,000 square metres.Most expansion will be in the Monoprix standard supermarket format and the Franprix and Leader Price discount banners.
Casino's international sales rose 70 per cent in the first quarter, bolstered by excellent performances in Latin America and Asia, which saw organic growth rise 18.6 per cent and 10.9 per cent respectively.
In Thailand the group delivered double-digit organic growth, reflecting increased sales through an aggressive expansion plan, while the US enjoyed a 14 per cent rise in consolidates sales.
The international division now contributes to 30 per cent of business revenue, with sales reaching €1.76bn.