Hyundai Motor Co delivered an earnings surprise with quarterly profit more than quadrupling, aided by a strong performance in the fast-growing Chinese and Indian markets and growing share in the United States.

South Korea's Hyundai <005380.KS>, which scored record sales in the United States last month with the launch of the revamped Sonata sedan and Tucson sport utility vehicle, is expected to keep its strong momentum in the current quarter with the global economic recovery.

But momentum may ebb in the second half of the year as the strengthening won against the yen reduces Hyundai's price competitiveness relative to Japanese rivals led by Toyota Motor Corp <7203.T>.

Hyundai, with affiliate Kia Motors <000270.KS> the world's fifth largest carmaker, earned a 702.7 billion won ($634.4 million) operating profit in the quarter ended March, versus 153.8 billion won a year ago, it said on Thursday.

The results easily beat a mean forecast of 573.6 billion won from 25 analysts surveyed by Thomson Reuters I/B/E/S and compared to a record 837.2 billion won the three months to December, when its smaller cars appealed to recession-weary buyers.

Hyundai said its net profit jumped five-fold to a record 1.1 trillion won from a year ago.

Shares in Hyundai, which leapt to a record earlier this month, extended gains after the results, rising 1.2 percent to 126,000 won by 0505 GMT, versus an 0.7 percent fall in the benchmark KOSPI <.KS11>.

Earnings at the top South Korean automaker are set to strengthen in the current quarter with the launch of its upgraded Elantra compact model later this month, while Toyota is struggling to clean up after massive safety recalls.

Hyundai's cost structure is also set to improve as more new cars are built on an integrated platform and an increase in overseas production and higher utilization of its factories eases the blow from the stronger won, analysts say.

Ahead of the earnings, Hyundai was forecast to post a 9 percent rise in operating profit to 2.4 trillion won this year, according to Thomson Reuters I/B/E/S. (Reporting by Kim Yeon-hee; Editing by Jonathan Hopfner)