Hyundai Motor Co. and its affiliate Kia Motors Corp. saw their U.S. market share exceed 10 percent for the first time in May, mainly thanks to robust demand for new models.

The automakers under the wing of Hyundai Motor Group sold 107,426 vehicles in the United States last month, up 21 percent from a year earlier.

They captured 10.1 percent of the American market, where the total sales of global automakers came to about 1.06 million units.

Kia Motors sold 48,212 units, posting a growth rate of 53.4 percent. Hyundai Motor posted 21 percent in yearly growth with sales of 59,214 vehicles.

“We had brisk sales in overseas markets including the U.S.,” a Hyundai company spokesman said. “By strengthening power as a global enterprise, we will continue to achieve the sales goal.”

The Genesis sedan’s sustained growth trajectory continued with May representing the 23rd consecutive month of year-on-year sales increases for Hyundai’s premium car.

The Equus sedan continued its strong launch, with sales and market share exceeding targeted levels.

While Hyundai sales were strong in all states of the U.S., California was the brightest spot, with sales up 95 percent for the first five months, compared to 2010.

But performance was below predictions from research centers that the Korean automotive group would grab third place in the sales rankings in May.

U.S. auto giant General Motors topped the list with sales of 221,192 units, followed by Ford Motor with 191,529, Chrysler with 115,363 and Japan’s Toyota Motor with 108,387.

“While we’ve still got a lot of work to do, we’re getting good responses to our consumer-driven Hyundai recipe ― assurance programs like Trade-In Value Guarantee and America’s Best Warranty, industry-leading fuel economy, and the freshest designs in the industry,” Hyundai Motor America’s president and CEO John Krafcik was quoted by a foreign news agency as saying.

During the first quarter of the year, Hyundai Motor Group’s share of the U.S. market for midsized sedans rose to a record high, industry data showed.

Meanwhile, according to industry data, 66,554 units of Hyundai Motor’s Sonata and Kia Motors’ K5, known as the Optima in overseas markets, were sold in the U.S. during the first three months of the year, giving the companies a combined midsized sedan market share of 15.1 percent.

In terms of units sold, Hyundai Motor Group’s first quarter midsized sedan sales increased 62.3 percent compared to the 41,013 units ― the Sonata and the previous Optima which was marketed as the Lotze in Korea ― sold during the same period last year.

By Kim Yon-se  (kys@heraldcorp.com)