Hyundai Motors and Kia Motors saw their market share in the United States reach nearly 15 percent in July, having already grabbed more than 15 percent for the mid-sized sedan segment there.

The affiliated automakers posted 14.6 percent in market share for the American market with sales of 72,440 units last month, up 0.2 percentage point from a month earlier.

After capturing 10.5 percent of the market in 2010, Hyundai-Kia’s market share continued to increase ― 11.5 percent in January, 11.9 percent in March and 13.1 percent in April.

Hyundai Motor Group spokespeople attributed the marked progress in sales performance to growing popularity of mid-sized sedans such as the Hyundai Sonata and Kia’s K5.

In particular, Hyundai’s Sonata sold more than 20,000 units in the U.S. in July, up 17.1 percent from the same month last year.

For the first three months of 2011, Hyundai-Kia ranked third for the mid-sized sedan segment, capturing 15.1 percent of the market in the U.S. by selling 66,554 units of the Sonata and the K5 (known as the Optima in overseas markets).

The figure puts Hyundai-Kia in third place behind Toyota Motor and Nissan Motor in terms of mid-sized sedan market share.

In the first quarter of 2011, Toyota took 17.2 percent of the market while Nissan vehicles accounted for 15.6 percent. Honda Motor ranked fourth with 14.8 percent.

“It is noteworthy that the higher income brackets in the U.S. began acknowledging the technology of Korean automakers,” a Kia spokesman said.

While the K5 contributed less to the total sales, the sedan’s recent introduction to the U.S. has boosted Kia Motors’ presence in the mid-sized market by more than 50 percent.

In addition, the automotive group is boosting its presence in the U.S. luxury sedan market with Hyundai’s Genesis and Equus vehicles grabbing a significant portion of sales.

Hyundai Motor saw its Genesis sedan capture more than 10 percent of the U.S. market in the mid-luxury class for the first time in April.

By Kim Yon-se (kys@heraldcorp.com)