Hyundai Motor on Monday debuted the revamped Sonata sedan in Seoul, the most crucial launch for the carmaker this year as it seeks to regain the market share in Korea and overseas.

Hyundai said it plans to sell 63,000 Sonatas in Korea and 165,000 units overseas this year, and 338,000 vehicles in 2015.

“The Sonata has played a key role in elevating Hyundai’s presence in overseas markets while leading Korea’s automotive industry,” said Hyundai Motor president Kim Choong-ho in a statement at the launching event held in Seoul. “It will become a game-changer in the midsize sedan segment.”

The launch comes at a time when the nation’s largest carmaker ― globally at No. 5 ― struggles with stagnant car sales due largely to outdated models and constant strikes that have been eating into its global image.

Along with the new Genesis luxury sedan launched in November, Hyundai is aiming high with the seventh-generation Sonata, which the carmaker spent up to 450 billion won developing over the past three years.

The Sonata has sold about 6.8 million vehicles globally. It is the second-best-selling Hyundai car behind the Avante, known as the Elantra overseas.

Following the new Genesis, the refashioned Sonata is the second Hyundai model to feature the Fluidic Sculpture 2.0, an upgrade of the carmaker’s original design philosophy best represented by the iconic hexagonal grille.

The carmaker also emphasized that the new Sonata is safer than its key rivals such as the Toyota Camry, Volkswagen Passat and Honda Accord as it uses advanced high-strength steel for 51 percent of the framework, more than double the previous 21 percent.

Further, while the weight increased to 1,460 kilograms from the previous 1,415, fuel efficiency was improved by 17 percent at 12.1 kilometers per liter. The base 2.0-liter gasoline model has 168 horsepower and a torque of 20.5 kilograms per meter.

The much-anticipated diesel-powered model was not included in the lineup.

Prices range from 22.55 million won ($21,000) for the basic 2.0-liter model to 29.9 million won for the high-end 2.4-liter model.

Starting with the Korean launch on Monday, the Sonata will make its debut in other markets from the latter half of this year. Its U.S. debut will take place at New York Motor Show in April.

By Lee Ji-yoon (jylee@heraldcorp.com)