South Korea's top automaker Hyundai Motor Co. sold 52,000 vehicles in the United States in February, up 2 percent from a year ago, industry data showed Monday. The data showed that Hyundai's market share in the U.S. remained unchanged at 4.4 percent. Hyundai's smaller sister company, Kia Motors Corp., sold 41,500 units in the U.S., down 8 percent from a year ago. Its market share stood at 3.5 percent last month, down 0.44 percentage points from a year earlier. Hyundai and Kia ranked seventh in terms of sales in the U.S. last month as their combined market share accounted for 7.9 percent of all vehicles sold in the U.S., according to the data. Still, Hyundai and Kia, the flagship companies of Hyundai Motor Group, the world's fifth-largest automotive group, said they can boost sales in the U.S. in the coming months by introducing new vehicles, including a long-wheelbase Santa Fe. Last week, Hyundai Motor Group Chairman Chung Mong-koo pledged to ramp up efforts to boost its profitability and the brand value of vehicles.