An index of South Korea's leading economic indicators hit a near four-year high in March, signaling the economy is entering an expansionary phase, data by the Organization for Economic Cooperation and Development showed Thursday.

The Paris-based organization said the composite leading indicator for South Korea reached 102.0 in March, up 0.2 point from February and the highest since the 102.1 tallied in April 2010. March marked the ninth straight month of increase.

A reading above 100 means a country's economy is expanding. The leading index predicts economic conditions 6-9 months ahead and takes into account developments in the country's asset market, manufacturing sector, interest rates and consumer and business sentiments.

Among the 38 countries checked, South Korea had the fourth-highest reading after Slovenia, Spain and Estonia. The country scored above the 100.1 average for all economies checked.

The OECD data comes as Asia's fourth-largest economy is struggling to gain traction after a slower-than-expected expansion of 3.3 percent in 2014. Local policymakers have stressed the economy is on the mend but conceded that gains so far have been inconsistent, expecting growth to hover in the mid-3 percent range this year.

In its latest economic assessment report, the finance ministry said the country is starting to shake off the lethargy of the fourth quarter, even if industrial output, spending and investment on fixed assets are continuing to fluctuate from month to month.

Concern is growing over the nation's exports that contracted in the first four months of this year vis-a-vis the year before. The government said it will check what is causing the drop and come up with ways to arrest the slide, which could seriously undermine the economy that relies heavily on exports for growth.

The OECD data also showed CLI numbers for China falling for the sixth month in a row to 98.7 points. The reading for the United States also fell into negative territory to stand at 99.6 in March from 100.5 in October, indicating that the world's largest economy may slowdown in the coming months. (Yonhap)