(Adds details of earnings)
By Brad Haynes
SAO PAULO, July 28 (Reuters) - GPA SA posted a quarterly loss on Tuesday as weak sales, stubborn cost inflation and rising interest rates hammered Brazil's biggest retailer.
The company reported a net loss of 30 million reais ($9 million) in the second quarter, down from a net profit of 358 million reais a year ago, according to a securities filing.
Earlier in the day GPA's appliance unit, Via Varejo SA , said it was closing stores and eyeing acquisitions in response to a 21.8 percent plunge in sales.
The group reported that its workforce had dropped from about 158,000 employees at the end of March to 151,000 at the end of June, highlighting the retail layoffs that are driving unemployment as a sharp downturn rattles Brazil's economy.
GPA's net revenue rose just 6 percent from a year earlier, while a benchmark consumer price index rose nearly 9 percent.
The group's gross profit, or sales minus the cost of goods, slipped to 23.9 percent of revenue, down 2.0 percentage points from a year earlier due largely to aggressive pricing at online unit Cnova NV. Cnova reported a quarterly loss of 40 million euros ($44 million) last week.
Net income in GPA's food retail unit, the group's largest division, fell 44.1 percent to 102 million reais, below an average forecast of 110 million reais in a Reuters poll of analysts.
Earnings before interest, taxes, depreciation and amortization for the food division fell 13.6 percent from a year earlier to 482 million reais, missing an average forecast of 532 million reais.
$1 = 3.3562 Brazilian reais Reporting by Brad Haynes; Editing by Christian Plumb and Cynthia Osterman