South Korea's first-quarter economic growth fell to the lowest in three quarters, boosting concerns about a prolonged low-growth trend, central bank data showed on Tuesday.

Real gross domestic product (GDP) reached 371.85 trillion won (323.9 billion U.S. dollars) during the January-March period, up 0.4 percent from the previous three-month period, according to the Bank of Korea (BOK).

The first-quarter growth was the lowest since the second quarter of 2015 when the real GDP rose at an identical rate of 0.4 percent due to negative impacts from the Middle East Respiratory Syndrome (MERS) outbreak.

After bottoming at 0.3 percent in the fourth quarter of 2014, the growth rate turned upward at a peak of 1.2 percent in the third quarter of 2015, before falling again to 0.7 percent in the fourth quarter of last year and 0.4 percent in the first quarter of this year.

From a year earlier, the real GDP increased 2.7 percent in the first quarter. Gross domestic income (GDI) picked up 2.8 percent on a yearly basis.

The slowing first-quarter growth was attributable to both sagging exports and lackluster private consumption.

Last week, the BOK revised down its 2016 growth forecast for the economy from 3.0 percent to 2.8 percent on concerns about economic uncertainties at home and abroad.

The South Korean government predicted a 2016 growth above 3 percent, but private think tanks lowered their forecasts to the mid-range of 2 percent.

LG Economic Research Institute's 2016 growth outlook was set at 2.4 percent, with those by Hyundai Research Institute and the Korea Institute of Finance being downgraded to 2.5 percent and 2.6 percent respectively.

Private consumption reduced 0.3 percent in the first quarter from the previous quarter due to weak demand for durable goods and semi-durables. It was a downturn from rises of 1.1 percent in the third quarter and 1.4 percent in the fourth quarter of 2015.

The downturn indicated the weakening of consumer sentiment caused by economic uncertainties, while hinting that the government's measures to bolster up private expenditure are winding down.

Construction investment expanded 5.9 percent in the first quarter after declining 2.4 percent in the previous quarter thanks to a rise in building constructions and civil engineering works.

Facility investment tumbled 5.9 percent on a quarterly basis due to softer demand for general machinery and transport equipments.

Exports, which account for about half of the economy, reduced 1.7 percent in the first quarter from three months earlier on the back of falling shipments of oil products and automobiles. Imports shed 3.5 percent amid lower crude oil prices.

Intellectual property investments inched up 0.1 percent due to the increased investment in the software sector.

By industry, production among manufacturers dipped 0.2 percent in the first quarter after growing 0.7 percent in the previous quarter. Production among builders gained 3.2 percent in the quarter, up from a 0.7 percent growth in the prior quarter.