SEOUL (BLOOMBERG) - Trading in South Korea's Kosdaq exchange for smaller stocks was temporarily halted after the benchmark gauge plunged more than 8 per cent.

Trading was suspended for 20 minutes at 11:55 am in Seoul after the measure dropped 8.2 per cent. A loss of 15 percent would trigger another halt of 20 minutes, while a drop of 20 per cent would stop trading for the rest of the day, according to the bourse.

The decline is the biggest since December 2011. The Kospi gauge of larger companies slid 2.1 per cent.

Celltrion Inc was the biggest drag on the small-cap measure, plunging 13 per cent. The stock is still up 17 per cent this year, after more than doubling in 2015.