Shares in Samsung Electronics, the world's biggest smartphone maker, fell the most in nine months after an Chase cut its profit estimates.
Samsung shares fell as much as 5.5% in early trade in Seoul to a four-month low of 1,438,000 South Korean won.
an said weak demand for Samsung's flagship phone, the Galaxy S4, from Europe was likely to impact earnings.
It said it now expects S4 shipments this year to be 20 to 30% lower than its previous forecast.
It said the firm was expected to ship 7 to 8 million units per month from July. Last month, Samsung announced that it had sold 10 million S4 units within a month of the phone's launch.
an analysts were quoted as saying by Bloomberg news agency that the S4's "peak-quarter number seems way below our previous estimates".
an lowered its 2013 earnings forecast for Samsung by 9%.
Profit warnings from analysts of other South Korea-based firms this week also dented investor morale.
"It's a general consensus that the profitability of Samsung's mobile business will weaken," Young Park from Woori Securities said in a note to clients.
Samsung has been shifting its focus to cheaper smartphones as pete with Chinese manufacturers.
However, analysts said that such moves would put pressure on profit margins and slow growth momentum for its high-end