South Korean firms' business sentiment improved for the first time in four months in March thanks to the effects of newly released smartphones and cars. 
 
According to the Bank of Korea on Thursday, the business survey index(BSI) during March for all industries came to 73, up four points from the previous month. 

A reading below 100 means pessimists outnumber optimists. 

The index marked the first rise since November of last year.

South Korean manufacturers' business sentiment also increased four points to 73 this month. The index for the non-manufacturing sector rose by three points to 73, posting growth for the first time in six months.  

The BSI for all industries for next month remains steady at 76, with rising oil prices causing a mixed outlook.