Japan's Nikkei 225 came next with a 7.2 percent increase over the cited period, followed by France's CAC 40 with 6 percent, Germany's DAX with 5.1 percent, the US NASDAQ Composite Index with 4.9 percent and the Hong Kong Hang Seng Index with 3.5 percent.

Among emerging markets, Brazil's Bovespa Stock Index was the biggest gainer with 6.8 percent, trailed by the Philippine Stock Exchange Index with 2.4 percent and India's Mumbai Index with 1.8 percent.

In contrast, Thailand's benchmark SET Index fell 2.9 percent over the cited period, and the Shanghai Stock Exchange Composite Index tumbled 5.8 percent.

KOSPI's stellar performance was attributed to a combination of rising hopes for a global economic recovery, South Korean companies' robust earnings and brisk foreign buying of local stocks. 

Expectations for a recovery in the world economy have been growing on rebounds in manufacturing indexes of major economies, with South Korean companies posting better-than-expected earnings for the first quarter.

Samsung Electronics Co., the top-cap tech giant, saw its operating profit soar 48 percent on-year to nearly 10 trillion won ($8.9 billion) in the January-March period, bolstered by the robust chip business. The company is expected to even post an operating profit of up to 13 trillion won in the second quarter.

Foreign investors have also been piling into South Korean stocks this year, which are widely viewed as relatively undervalued. Offshore investors bought a net 7.1 trillion won of local shares between Jan. 1 and May 15.

Despite a recent breather, the South Korean stock market is forecast to continue its upward momentum, with expectations for policy initiatives by the new government likely to push the key index higher.

President Moon Jae-in of the Democratic Party took office on May 10, a day after scoring a landslide victory in the snap presidential election triggered by the impeachment and ouster of Park Geun-hye over a corruption and abuse-of-power scandal.

"The upward momentum of the South Korea stock market is expected to continue in the coming months in light of a recovery in global demand, South Korea's rebounding exports and improving corporate earnings," said Kim Yong-koo, an analyst at Hana Financial Investment Co.

Some market watchers, however, warned the South Korean market could face growing downside pressure in the second half of the year due to such potential risks as US rate hikes, uncertainty over President Donald Trump's policies and geopolitical risks. (Yonhap)