Portugal's largest retailer, Sonae, posted on Wednesday a small 0.7 percent increase in preliminary sales for last year, helped by a strong year-end performance that allowed the company to avoid a drop in sales expected by some analysts.

Sonae, which operates Continente hypermarkets, consumer electronics stores Worten and SportZone outlets of sporting goods, among other brands, said its sales rose to 4.85 billion euros ($5.28 billion) in 2015.

Caixa Banco de Investimento analysts expected Sonae's retail sales to have finished 2015 at 4.78 billion euros.

"Despite a strongly competitive environment ... Sonae's retail operations registered positive evolution trends in 2015, with all its units contributing positively to an increase in sales," Sonae said in a statement.

Sonae's food retail networks, which accounted for 3.49 billion in sales last year, posted a nearly 2 percent increase in fourth-quarter sales with a 3.4 percent rise in December alone, when like-for like sales rose 1 percent.

Sonae competes at home against Portuguese group Jeronimo Martins, Spain's Dia, Germany's Lidl and France's Auchan. Jeronimo Martins posted on Jan. 12 an 8 percent rise in net sales for last year, driven by its Polish unit Biedronka.

($1 = 0.9179 euros)