SEOUL—South Korea’s LG Chem Ltd posted a 20 percent fall in quarterly profit on Monday, hurt by a one-off expense associated with the recall of General Motors’ Bolt electric vehicles. It reported an operating profit of 727 billion won ($617.55 million) for the July-September period, versus 904 billion won a year earlier and an average analyst forecast of 893 billion won compiled by Refinitiv SmartEstimate. Earlier this month, LG Chem, which owns electric battery maker LG Energy Solution (LGES), said it would take a charge nL1N2R8085 of 620 billion won in its third quarter results in connection with the GM Bolt recall due to the risk of fire caused by rare battery defects. Revenue rose 41 percent to 10.6 trillion won, LG Chem said in a regulatory filing. LG and GM settled a $2 billion cost deal on the Bolt recall earlier this month, paving the way for LG’s battery …