The benchmark Taiex Index fell 2.1 percent to 7,538.08, the biggest drop since Dec. 19.
China Steel Corp. (2002) (2002 TT) retreated 1.5 percent to NT$28.75, the most since April 5. April pretax profit fell 81 percent from a year earlier to NT$708 million, it said in a statement to the Taiwan Stock Exchange.
Largan Precision Industry Co. (3008) (3008 TT) lost 0.6 percent to NT$477. The lens maker said April sales declined 1.5 percent from a year earlier to NT$1.16 billion, according to a statement to the stock exchange.
Tyntek Corp. (2426) (2426 TT) slumped 3.6 percent to NT$11.90, the biggest decrease since April 5. The light-emitting diode maker said April sales dropped 22 percent from a year earlier to NT$253.7 million, according to a company statement.
To contact the reporter on this story: Weiyi Lim in Singapore at email@example.com