Foxconn declined by its 6.9 percent limit to NT$183, its lowest since April 1, as of 9:17 a.m. on the Taiwan Stock Exchange, compared with a 0.8 percent gain in the Taiex index.

JPMorgan Chase & Co. cut its investment rating on Foxconn after the company reported first-quarter net income fell 23 percent to NT$1.24 billion (US$41 million). That missed all three analyst estimates compiled by Bloomberg. "The near-term direction of the stock is firmly negative, given sharp downward revisions in margin expectations," JPMorgan's Gokul Hariharan, who's based in Taipei, wrote in a report dated April 30. He cut the stock to "neutral" from "overweight" and lowered his price target to NT$170 from NT$275.

Hariharan estimates Foxconn's operating margin, the percentage of sales left after deducting operating costs, will be 8.1 percent in the second quarter, lower than his previous projection of 9.3 percent. He also cut his margin estimate for the full year.

Foxconn is a subsidiary of Hon Hai Precision Industry Co., the world's largest contract electronics manufacturer. Hon Hai shares declined 3.1 percent to a one-month low after first- quarter profit rose 2.9 percent, the slowest growth in almost seven years.