LG Group, one of South Korea's biggest corporations, has been reeling after two deadly accidents at its LG Chem facilities

LG Group chairman Koo Gwang-mo apologised Wednesday over two fatal accidents at LG Chem facilities in the past two weeks, reports said, including a gas leak in India that killed 12 people.

LG Group is the fourth-biggest of the chaebols, the family-controlled conglomerates that dominate business in South Korea, the world's 12th-largest economy.

LG Chem, the group's key subsidiary and South Korea's largest chemical company, is reeling from the deadly gas leak at its LG Polymers India subsidiary, which left 12 residents dead and saw more than 1,000 hospitalised.

On Wednesday, a fire broke out at LG Chem's plant in Seosan, around 120 kilometres south of Seoul, killing a researcher and injuring two workers.

"I express my deep condolences and consolation to victims and their families," Koo said at the Seosan plant, according to Yonhap news agency.

"I am very sorry for causing concern to many people," Koo added, noting that management felt "heavy responsibility" for the safety accidents.

LG Chem produces petrochemicals, plastic resins, and engineering plastics, and has plants across South Korea and around the world, from the United States and Brazil to China and Australia.

The company also manufactures industrial and electronic materials and has emerged as one of the top battery suppliers for hybrid and , with customers including Mercedes Benz, Volvo, Volkswagen, and BMW.

LG Chem recorded sales of $24.5 billion last year and an operating profit of $800 million, according to its website.