Models pose with the new Hyundai Genesis today during an unveiling in Seoul, South Korea. The luxury sedan has been revamped for the first time since 2008. Associated Press

NAMYANGJU, South Korea — Hyundai has revamped the luxury Genesis sedan for the first time since 2008, attempting to elevate its brand and grab a bigger share of U.S. car sales as competition from American and European automakers erodes Hyundai’s dominance in its South Korean stronghold.

Since entering the U.S. in 1986, Hyundai Motor has carved out a niche with buyers looking for cheaper alternatives to Toyota’s big-selling Camry and Corolla marques. Sophistication, power and style have not been qualities typically associated with its brand. Now, South Korea’s largest automaker hopes to expand sales by competing more boldly with BMW, Mercedes-Benz, Toyota’s Lexus and other high-end models.

The new Genesis, unveiled today, will be available in the U.S. early next year and will be the first Hyundai luxury sedan sold in Europe. Y.J. Ahn, a director of Hyundai’s American business, said the redesigned sedan will help drive 10 percent growth in Hyundai’s U.S. sales next year from 734,000 vehicles expected this year. The automaker’s U.S. market share declined to 4.7 percent in the first nine months of this year from 4.9 percent in 2012.

“This is a chance to raise Hyundai’s image in the premium car market,” said Ahn.

The South Korean automaker, which with affiliate Kia Motors forms the world’s fifth-biggest car manufacturer, is in need of a boost.

South Korea’s free trade agreements with the U.S. and European Union have opened Hyundai’s home market to greater competition. Last year, almost one in every two vehicles sold in South Korea was made by Hyundai. Last month, Hyundai’s share had dropped to 42 percent.

Japan’s policy, meanwhile, of weakening the yen has given Japanese automakers a competitive edge in international sales.