* Q3 net profit 2.3 trln won vs consensus of 2.17 trln won
* China, Brazil sales strong on new factories
* Aging models, tight supply, competition crimp U.S., Korea sales
* Shares down 1.9 pct in flat market
SEOUL, Oct 24 (Reuters) - South Korean automaker Hyundai Motor Co posted a small quarterly net profit gain, with its strong sales in China and Brazil overshadowed by lacklustre performances at home and in the United States.
Hyundai Motor, once a stellar performer in the global auto industry, is losing some of its shine. Its U.S. market share is stagnating as a weaker yen gives its Japanese rivals a boost. The South Korean firm is also being squeezed by the growing popularity of BMW and Volkswagen in its home market, following bilateral trade deals.
The intensifying competition is adding pressure on Hyundai Motor at a time when it is already grappling with capacity constraints and aging models such as the Sonata.
Hyundai Motor, the world's fifth-biggest carmaker along with affiliate Kia Motors Corp, said on Thursday net profit rose 3.9 percent to 2.3 trillion won ($2.2 billion) in the third quarter ended September from a year earlier. That was slightly above an average forecast of 2.17 trillion won, according to Thomson Reuters I/B/E/S.
The automaker posted an operating profit of 2.0 trillion won and revenue of 20.8 trillion won.
Total vehicle shipments climbed 11 percent to 1.1 million in the third quarter as labour strikes at home were offset by new production in China and Brazil.
The increased output in China and Brazil boosted sales in those markets and countered sluggish demand in the United States and South Korea.
Hyundai Motor increased sales incentives in the United States and South Korea in the third quarter to woo customers away from rivals and to boost demand for its aging models, analysts say.
The South Korean won has also strengthened about 13 percent against the yen so far this year, giving Hyundai Motor's Japanese rivals a bigger competitive edge.
Hyundai Motor shares fell 1.9 percent to 253,500 won in Seoul trading as of 0549 GMT after jumping 16 percent over the past three months on hopes its upcoming models Genesis and Sonata may help revive earnings growth. Brokerages such as Macquarie Securities and BNP Paribas this month raised the target share price of Hyundai Motor.