Dutch supermarket group Ahold on Thursday said it was able to increase sales in the third quarter of 2012, although the difficult economic circumstances put theprofit under pressure. The net sales of Ahold amounted to 7.6 billion euros (9.7 billion U.S. dollars), an increase of 3.7 percent at constant exchange rates compared to the same period last year. Operating income, meanwhile, stood at 289 million euros, a decrease of 3.7 percent. The net profit fell by more than 45.9 percent in the July-September period to 139 million euros and the underlying operating margin was 4.1 percent. \"Sales growth in the United States was modest,\" CEO Dick Boer explained in a press release. \"Through stringent cost control, we were able to deliver a solid margin performance. In the Netherlands, we were pleased with a strong sales performance, as our value investments gained traction,\" he said. Ahold expected persistently difficult market conditions. \"We remain cautious in our outlook and expect market conditions to continue to be difficult,\" Boer said. \"We will closely monitor the potential impact of rising food commodity costs, particularly in the United States. We are confident that we are well on track to execute our strategy and we will continue to invest in growth,\" he said.