Two former Kia executives will take over domestic and overseas sales responsibilities from Hyundai President and co-CEO Steve S. Yang, who has resigned unexpectedly for personal reasons.

Yang, whose departure is effective Oct. 1, is credited with bringing Hyundai through a difficult global recession while gaining sales and market share in both North America and Europe.

“We liked Steve Yang very much and do not know why he has left the company, but he will continue his affiliation in a consulting capacity,” a spokesman tells WardsAuto.

Replacing Yang are two executives who had stellar careers with affiliate Kia prior to joining Hyundai recently.

Some analysts say Kia has outperformed Hyundai in the domestic and some overseas markets, speculating the two executives were brought over to provide a spark.

Named president is Choong Ho Kim, 60, who will head up the business-strategy planning group and domestic business and marketing strategy division.

Previously, he held the position of senior executive vice president-domestic sales. He occupied a similar post at Kia and has been with the Hyundai Automotive Group for 31 years.

Seung Tack Kim, 54, is promoted to senior executive vice president-overseas business division, from his former position as executive vice president-global business planning.

He joined Hyundai last year, after making a mark as executive vice president in charge of Kia’s European business. Prior to that he headed Kia’s global business policy group.

Yang was named president and CEO in January 2009. Before that he had served as president and CEO of Glovis, a logistics firm affiliated with Hyundai.