Samsung Electronics Co. slumped to a 10-month low in Seoul on disappointment with its latest smartphones to challenge Apple Inc.

The stock dropped 3.2 percent to 1,104,000 won on Monday, its lowest since Oct. 28. Samsung has fallen 17 percent this year and is headed for its third straight annual decline.

Samsung unveiled the Galaxy Note 5 and S6 Edge Plus with a wraparound screen last week as it tries to revive profit growth and regain sales from Apple and Chinese producers Xiaomi Corp. and Huawei Technologies Co. The 5.7-inch (14.5-centimeter) screens and addition of a mobile payment service are meant to help Samsung stand out from the array of inexpensive devices using the same Android operating system.

“Last week’s unpacking event was very disappointing,” said Yoo Eui Hyung, an analyst with Dongbu Securities Co. in Seoul. “We should now admit that new smartphones are no longer a thing that can reverse the profit decline.”

The Suwon, South Korea-based company brought the release dates forward to get the jump on successors to the iPhone 6 and iPhone 6 Plus that are expected next month.

Samsung earnings have fallen for five straight quarters. Second-quarter profit missed analyst estimates after the company misjudged market demand for its S6 devices, which prompted Samsung to cut prices for the four-month-old devices.