An Asiana Airlines plane takes off from Incheon International Airport, Jan. 14. Korea Times photo by Shim Hyun-chulAsiana Airlines Inc. said Thursday its net loss widened in the second quarter from a year earlier, hit by rising fuel costs and a weaker Korean currency.The second-quarter net loss stood at 328.6 billion won ($231 million), compared with a loss of 233.2 billion won for the same quarter last year, the company said in a statement.Asiana Airlines also posted an operating loss of 295.1 billion won in the second quarter. Sales fell 7.7 percent on-year to 1.54 trillion won.This week, shareholders of Asiana Airlines approved the airline's merger with larger rival Korean Air Co., wrapping up nearly six years of the latter's acquisition process.