South Korea's second largest automaker, Kia Motors, said it posted a record profit last year thanks to brisk overseas sales and increased returns in investment in affiliated firms.

Net profit surged 30.4 per cent from the previous year to 3.5 trillion won ($US3.1 billion or $A2.93 billion) in 2011, the company said in a statement.

Sales jumped 20.6 per cent on-year to 43.2 trillion won in 2011, with operating profit up 41.6 per cent to 3.5 trillion won.

It sold 2.48 million cars last year, up 18.6 per cent, thanks to solid sales of new models and the company's improved brand image, the automaker said.

Overseas sales were particularly brisk despite the eurozone crisis and the global economic slowdown, it said.

Sales in the United States surged 36.3 per cent to 485,000 cars last year while domestic sales crept up a mere 1.7 per cent to 492,000.

Sales in China surged 29.9 per cent to 433,000, while those in the European market increased 12.2 per cent to 290,000.