BRASILIA, Oct 19 (Reuters) - Carrefour Brasil (CRFB3.SA), one of Brazil’s largest retailers and owned by Carrefour SA (CARR.PA), reported an 8% increase in gross sales for the third quarter, the company said in a filing on Tuesday. Sales by its wholesale division Atacadao jumped 14% over the same quarter last year, while its retail business had an 8% drop in gross sales for the quarter. On-line sales plummeted 20% over the same period a year ago, Carrefour said.