South Korean firms' business sentiment remained flat for the second consecutive month in June due partly to rising prices of raw materials. 

According to the central Bank of Korea on Friday, the business survey index(BSI) for all industries stood at 88 for June, unchanged from the previous month.  

The index rose in March and April and remained flat for two straight months since. A reading below 100 means pessimists outnumber optimists.  

The BSI for manufacturers gained two points on-month to 98 in June, the highest since April 2011 when it marked 99. 

The BSI for non-manufacturers, which includes restaurants, wholesale and retail businesses, remained flat at 81. 

Local firms' BSI for July rose two points on-month to 90.