Hyundai Motor Co drove up sales in France by 40 percent last month and had a record September in the United States, but it has since had nearly $7 billion wiped off its market value as investors query the South Korean automaker's go-slow on expanding capacity.

Hyundai, which with affiliate Kia Motors is the world's fifth-biggest carmaker, has not announced plans for a new plant for at least two years, part of a strategy to focus on brand and quality over aggressively chasing market share - but this has left it short of cars to sell into a recovering U.S. market, where Japanese rivals have muscled back in, as well as in emerging markets such as India.

In a summary note this week, Standard & Poor's forecast Hyundai and Kia would lose global market share by 2014.

The group is likely to say later on Thursday that July-September net profit rose 11 percent to 2.13 trillion won($1.93 billion), with growth hobbled by the firm's costliest-ever labour strikes in July-August in its home market

-where it makes nearly half of the vehicles it sells globally.

Lost production from those strikes will have overshadowed sales gains in markets from Europe and the United States to China - where Japanese brands suffered in the fallout from a diplomatic row over disputed islands in the East China Sea.

Analysts have trimmed their earnings forecasts for Hyundai in recent weeks to reflect the impact of the strikes - half of the 28 estimates for net profit are new or have been revised since Oct. 5, pushing down estimates by an average 7.4 percent, according to Thomson Reuters StarMine data.

LONG DRIVE

While earnings should pick up speed again in the current quarter as buyers like the value-for-money a Hyundai car offers in a weak global economy, the company's reluctance to expand capacity significantly has investors worried about its ability to sustain strong profit growth over the long-term.

Hyundai's global sales are expected to rise by around 7.5 percent this year and next year - good, but not as good as the double-digit growth in 2009 to 2011 - according to analysts' estimates compiled by Reuters. Net profit growth is seen slowing to 8 percent next year, from an estimated 14 percent this year and 35 percent last year.

Those concerns have seen Hyundai's shares slump more than 13 percent this month, hitting 7-month lows on Wednesday. Over the same period, shares in Honda Motor Co Ltd, Nissan Motor Co Ltd and Toyota Motor Corp have risen around 7 percent, 4 percent and 2 percent respectively.

"The reason for Hyundai's share price fall is very simple;growth deceleration," said Ahn Young-hoe, a fund manger at KTB Asset Management, adding that South Korea's won currency  has also been stronger against the dollar, eating into overseas profits when they are repatriated.

The industrial action - which cost Hyundai more than 82,000 cars worth $1.5 billion - hit the South Korean market hardest, but Hyundai managed to keep total July-September shipments flat as stocks of cars made overseas kept sales ticking over.