Turkish Petroleum Refineries (TÜPRAŞ) has measured an increase in its net profit of 39 percent in the first nine months of this year, compared to the same period last year, the company said in a statement on Friday. TÜPRAŞ said the company's net profit had reached TL 1.735 billion ($603 million) within the period, up from TL 1.246 billion in 2014. "In first nine months, our domestic sales increased 27.4 percent year-on-year due to high demand as oil prices are low," the company said. Net sales decreased to TL 28 billion between January and September of this year from TL 30.6 billion in the same period of 2014, the company said. Its sales by volume totaled 20.9 million tons, an increase of 4.7 million tons from the same period of last year. The oil refinery, Turkey's largest industrial enterprise and owned by Koç Holding, has an annual processing capacity of 28.1 million tons of crude oil. TÜPRAŞ Director General Yavuz Erkut will retire by the end of the year and be replaced by current assistant general manager, İbrahim Yelmenoğlu, the statement said. Sales have improved for oil refineries as the low cost of oil has allowed them to reduce prices.