SEOUL - Hyundai Motor, South Korea's No1 carmaker, saw its first-quarter operating profit halve from a year earlier on weak demand from China and the United States, the world's top two automobile markets, a regulatory filing showed Thursday.

Hyundai's operating profit was 681.3 billion won ($631 million) in the January-March quarter, down 45.5 percent from the same period of last year. It missed market expectations of about 900 billion won ($830 million).

Revenue shed 4 percent over the year to 22.44 trillion won ($20.8 billion) in the March quarter, and net income tumbled 48 percent to 731.6 billion won ($680 million).

Hyundai's global car sales fell 1.7 percent over the year to 1,049,389 units in the first quarter. Excluding China, the company's global auto sales gained 2.8 percent to 883,827 vehicles.

Overseas car sales by Hyundai reduced 2.8 percent to 880,186 units in the quarter due to softening demand from China and the United States that offset higher demand from emerging economies such as India, Russia and Brazil.

The South Korean currency's appreciation versus the dollar also contributed to the falling profit of Hyundai, South Korea's biggest automaker.