Operating profit came to 771 billion won (US$691 million) in the April-June period, compared to 664 billion won posted in the same period a year earlier, LG Electronics said in its earnings guidance report.
Sales rose 3.2 percent over the cited period to reach 15 trillion won.
LG did not offer performance and net profit estimate reports for each business division. The company will deliver its finalized earnings report later this month.
Operating profit slid 30.4 percent from January-March of 2018.
Industry watchers said the on-quarter decline apparently came on increased marketing expenditures, along with sluggish sales of smartphones.
LG, however, said it was the first time for the company to post sales above 30 trillion won over a January-June period.
In the first six months of 2018, LG raked in 30.1 trillion won in sales, along with a record 1.87 trillion won in operating profits.
Analysts said the strong sales of home appliances and TVs were apparently the driving force behind the record-breaking earnings for the first half of the year.
The home entertainment business posted an operating profit-to-sales ratio of 14 percent in the first quarter, and the company is expected to have maintained a 10-percent level for the April-June period.
The mobile communications business, which oversees smartphones, however, is expected to have continued posting losses. If the division remained in negative territory for the three month period, it would virtually mark the 13th consecutive quarter for LG losing money in this business area.