Prosecutors demanded a six-year prison term for Hyundai Motor Chairman Chung Mong-koo on Tuesday in his appeal trial against a three-year sentence handed down in February for embezzlement.
A team of three prosecutors arguing the case said that Chung's crimes have dealt a serious blow not only to his company, but also to South Korea's image overseas.
"The sentence is too light," one of them told the court.
In February, Chung, 69, was sentenced to three years in jail for breach of trust and embezzling the equivalent of more than $100 million in company funds to set up a slush fund.
Chung's lawyers want a suspended sentence, meaning the executive would not serve prison time unless involved in other crimes. He is free on bail and runs the world's sixth-largest automaker, sometimes traveling overseas.
Chung has a reputation for hands-on management and key decisions were delayed when he was jailed for two months following his arrest in April 2006.
His lawyers have called for leniency, citing the contributions Chung has made to the South Korean economy.
On Tuesday, they said that Hyundai is at a crucial stage and cannot afford to lose Chung's leadership as it expands aggressively overseas.
Chung himself pleaded for the chance to avoid jail and make amends.
"I ask for an opportunity for me to contribute to the company and the national economy one last time," he told the court.
Chung, one of South Korea's richest men, has repeatedly expressed regret and vowed to donate $1.1 billion worth of personal assets to society.
"I'm very sorry to have created big problems with this case and raising concerns of the people," Chung told the court Tuesday.
Three other Hyundai officials facing similar charges were also convicted in February, but all were given suspended sentences.
Appeal courts have in the past sometimes granted more lenient sentences than lower court rulings in cases involving business tycoons.
In 2005, Chey Tae-won, CEO and Chairman of South Korea's leading oil refiner, SK Corp., had the three-year prison term he received for accounting irregularities suspended by the Seoul High Court.
The court said a ruling in Chung's appeal would be handed down on July 10.