(Adds comparison to competitor Carrefour, context and details)
By Gabriela Mello
SAO PAULO, April 24 (Reuters) - Brazilian supermarket chain Grupo Pão de Açúcar SA on Wednesday posted first-quarter sales up 12 percent from a year ago, closing the gap on Carrefour Brasil, the market leader in Latin America's largest economy.
GPA, which is owned by France's Casino Guichard Perrachon SA , reported gross revenues of 13.8 billion reais ($3.46 billion), driven by gains in its wholesale division, Assaí.
On Tuesday, Carrefour Brasil posted a 10 percent increase in gross sales to 14.2 billion reais, as growth in its wholesale unit Atacadão more than compensated for a flat performance in the retail division.
In recent quarters, the wholesale format - where consumers can buy discounted goods directly in a warehouse setting - has gained popularity amid the slow recovery of the Brazilian economy from the worst recession in decades.
Atacadão leads the segment in sales but faces increasing competition from new players, as well as Assaí.
Assaí total sales grew by 26 percent in the first three months of 2019, as a result of an expansion plan to open 20 new stores per year.
On a like-for-like basis, GPA's gross revenue rose 7.5 percent year-on-year, excluding calendar factors. Its Assaí division recorded a 10.7 percent rise in same-store sales, while the retail division which includes the Extra and Pão de Açúcar brands posted 4.8 percent growth.
GPA shares traded on the Brazilian stock market ended 0.3 percent down on Wednesday, while Carrefour Brasil lost 1.8 percent.
($1 = 3.9911 reais) (Reporting by Gabriela Mello; Editing by Richard Chang and Rosalba O'Brien)