The earnings of Samsung Group and Hyundai Motor Group, Korea’s two biggest conglomerates, accounted for 81 percent of the total profits of the country’s top 30 business groups last year, up from 47.5 percent in 2010.

The increased proportion may be viewed as showing Samsung and Hyundai have continued to expand their presence in the Korean economy. However, a closer look at the data released by a local research firm Sunday suggests the real problem is the performance of other companies has been too sluggish.

In fact, the combined net profit posted by the two largest groups decreased by 11.5 percent from 38 trillion won ($35 billion) in 2010 to 33.6 trillion won last year. The figure for the remaining 28 conglomerates plummeted by 81 percent from 42.1 trillion won to 7.9 trillion won over the cited period.

The lackluster performance of Korea’s big businesses results from decelerating exports coupled with sluggish domestic spending. The slowdown in export growth is attributed to a combination of Japan’s weaker currency, increasing challenges from Chinese companies and the prolonged slowdown in the global economy.

According to figures from the Korea Trade-Investment Promotion Agency, the growth rate of Korea’s exports slid from a whopping 22 percent in 2010 to 5.6 percent in 2012 and further to 4.4 percent last year. The country’s overseas shipment shrank by 2.8 percent from a year earlier in the first quarter of this year. Car exports, in particular, dropped by 10.1 percent on-year in the January-March period, mainly due to stiffer competition from Japanese automakers, showed separate data released by the Korea Customs Service on Wednesday.

It is unlikely that Korean corporations’ profitability will improve this year, given business conditions are expected to remain unfavorable both at home and abroad. Decreasing corporate profitability will lead companies to refrain from expanding investments, thus holding back the economic recovery.

The Finance Ministry has clung to its 2015 growth forecast of 3.8 percent. But the Bank of Korea recently cut its outlook to 3.1 percent from an earlier estimate of 3.4 percent, citing the weaker-than-expected recovery pace.

The International Monetary Fund last week lowered its 2015 growth prediction for Korea to 3.3 percent from the 3.7 percent forecast in January.

Economic recovery could be facilitated by enhancing the performance of large corporations and channeling the effect into their parts suppliers and households. Big businesses should redouble efforts to find new growth engines and improve productivity. The government needs to encourage such corporate endeavors by helping create more favorable investment conditions through drastic deregulation.

It is also necessary to pay more heed to the increasing pressure a strengthening won is putting on Korean companies. Over the past month, the value of the Korean currency rose by 3.65 percent against the dollar, marking the steepest pace of increase among major Asian currencies.

Nearly 40 percent of the 159 Korean manufacturers relying on exports for more than half of their sales made profits insufficient to pay interest on loans taken by them last year. Their difficulties are expected to grow this year, with major advanced and emerging economies set to keep or expand aggressive monetary easing policies. Economic policymakers here may now need to give more serious consideration to ways to help the value of the won remain at an appropriate level.