SAO PAULO, Oct 31 (Reuters) - Carrefour Brasil reported a nearly 60% year-on-year decline in net profit for the third quarter, hit mainly by lower sales in its retail unit, the company said on Tuesday.

The Brazilian arm of French retailer Carrefour said that its profit reached 132 million reais ($26.19 million) in the three-month period.

Net sales from the group fell 3.3% to 25.51 billion reais, as its retail operations saw a 14.2% decline in sales due to a conversion of 32 retail stores into wholesale.

Like-for-like sales for the July-to-September period shrunk for both the retail and wholesale units, Carrefour said.

"With food deflation pressuring revenue, we drew on our unique experience, negotiating with suppliers, implementing efficiency measures and cutting costs to protect profitability," said the firm's CEO, Stephane Maquaire, in a statement.

Operating expenses landed at 3.69 billion reais, growing 3.3% from the previous year, but 2.8% below the previous three months.

Adjusted earnings before interest, taxes, depreciation and amortization (EBITDA) fell 13.4% to 1.47 billion reais. Profitability, measured by the adjusted EBITDA margin, stood at 5.7%, losing 0.7 percentage points from the previous year.

The retailer's net cost of debt was 698 million reais in the period, up 9.9% on the previous year, mainly due to higher interest on loans. (Reporting by Andre Romani; Writing by Peter Frontini; Editing by David Alire Garcia and Sandra Maler)