LG Chem Ltd., South Korea's top chemical firm, soared to a 52-week high on Thursday on solid earnings and hopes for its burgeoning battery business, industry sources said.

LG Chem traded at 377,500 won ($345) on the Seoul bourse as of 10:05 a.m., up 3.14 percent from the previous session's close and becoming the seventh most valued firm on the local stock market, and bypassing Internet portal operator Naver and Samsung C&T, the de facto holding firm of Samsung Group.

Over the past two months, LG Chem has gained over 30 percent, aided by its sound bottom line. 

For the second quarter of the year, LG Chem logged an operating income of 727 billion won, up 19 percent from a year earlier. Its sales also rose 22 percent on-year to reach 6.38 trillion won in the April-June period.

Last year, the company posted a net profit of 1.28 trillion won, rising from 1.15 trillion won a year earlier.

The company aims to log 22.82 trillion won in sales this year, up 10.5 percent from last year, it said earlier. LG Chem also said it plans to spend 2.76 trillion won this year, sharply up 40 percent from 2016.

"Spreads on its key products such as polyvinyl chloride have remained firm and its battery business has turned around," said Yoon So-hyun, an analyst at BNK Investment & Securities. "The spreads will further expand down the road."

LG Chem said earlier its battery unit logged an operating income of 7.5 billion won on sales of 1.12 trillion won during the second quarter.

LG Chem entered the EV battery business in 2009. The company has supplied batteries to global carmakers, such as Audi and Renault-Nissan, as well as others. It currently operates an EV battery plant in China, the United States and South Korea.

In 2015, LG Chem started the operation of its new EV battery plant in China, eyeing growing demand on the back of Beijing's plans to tackle air pollution by introducing more eco-friendly cars. (Yonhap)