Nimble Asian technology firms led by Samsung Electronics appear well placed to slow the runaway success of Apple, as news of its visionary CEO Steve Jobs taking medical leave battered Apple's shares.

Job's latest medical leave, the third time since 2004, comes at a time when the world's most valuable technology firm faces the biggest threat from Google, through its Android mobile operating system, which has seen torrid growth as the preferred choice of both iPhone and iPad rivals.

Samsung, at the forefront of the long queue of rivals determined to halt Apple's runaway boom in smartphones and tablets, is seen as a key threat, and its shares jumped more than 3 percent to a record, partly helped by such expectations.

There'll be no fundamental change in Apple but the news of Jobs taking leave could sentimentally hit Apple shares and offer investors an opportunity to take profits from its shares, which have risen so much recently, said Lee Seung-woo, an analyst at Shinyoung Securities.

Then Samsung is the best alternative for investors seeking exposure to the tech sector as it's the most formidable threat to Apple for now.

Apple's surprise announcement -- made on a U.S. market holiday -- dragged its shares down more than 6 percent down in European trading on Monday. They are up 62 percent in the past 12 months on the Nasdaq stock exchange.

Samsung, under the Lee family, has become a top global brand in the space of 10 years and now boasts a market value of $136 billion, equal to the combined value of Sony Corp, Nokia, Toshiba Corp and Panasonic corp.

Still it's worth less than half of Apple, which boasts $320 billion market value.

A rapid rise of competitors adopting Android phones would also mean little differentiation and weaker profit margins for many Asian firms rushing to introduce copycat products, compared with Apple's estimated 40 percent-plus margins on the iPhone.

Sony has also joined the fray, declaring it wants to become No.2 tablet maker after Apple by 2012, although it has yet to unveil its own tablet and needs to regain the ground lost to Asian rivals first before targeting Apple, analysts said.

Sony... has branched out into movies, games music and other areas and that has meant Sony has had to spread its people across a wide set of objects. It means they lose sight of what consumers want, said Akihide Knugawa, a fund manager at T&D Asset Management, which owns Sony shares.

Also in the past Sony didn't have to compete against Taiwanese or Korean companies...Samsung's strength plus exchange rates (of a weaker won) make it difficult for Sony to come up from behind.

MIXED BAG

Deemed irreplaceable by many Apple fans and investors, pancreatic cancer survivor Jobs said on Monday he would take medical leave. The announcement, which came just a day ahead of the company's quarterly results, did not specify why or for how long he would be absent, unlike the previous time.

The announcement revived concerns over the long-term future of Apple, although Jobs said Chief Operating Officer Tim Cook would take responsibility for day-to-day operations once again.

The impact of the Apple news could be mixed on the Asian technology sector. Many firms, including Taiwan-based Hon Hai, South Korea's LG Display and even Samsung depend on the iPhone and iPad maker by manufacturing the hot selling devices and by supplying display, chips, phone cases and other accessories.

But analysts said the impact on Apple's operations and its Asian rivals and partners should be limited in the short term, since its product line-up was strong, although his absence would be a worry if it became prolonged. Cook ran day-to-day operations during Job's last absence in 2009.

Apple's roadmap is all set and its iPhone 5 is ready to go, leaving little room for competitors to cut into its share, said Bonnie Chang, an analyst at Yuanta Securities.

HTC may have to design more cutting-edged high-end products, but its roadmap for this year has already been laid out, it may have to wait till H2 if it wanted to do anything.

Shares of Samsung, the world's top memory chipmaker and No.2 handset vendor, jumped 3.4 percent on Tuesday before closing up 2.1 percent. Shares of Hon Hai, which counts Apple as its major client, were unchanged, those of LG Display, which supplies flat screen for Apple, fell 0.1 percent and smartphone maker HTC dropped 0.2 percent.

Android has rapidly overtaken Apple and Research in Motion's BlackBerry to become the second-most popular platform worldwide after Nokia's Symbian, and the most popular in North America and east Asia.

Riding a boom in Android-based phones, Samsung has sold 10 million units of Galaxy S smartphone since its June launch and around 1 million units of the Galaxy Tab tablet since October.

It has also launched the Nexus S smartphone recently based on the latest version of Android and plans a series of new product launches in February to double its smartphone sales this year to around 50 million units.

Strong sales of such devices and ensuing launches of copycat products by the likes of Lenovo Group, Motorola and Research In Motion are set to drive up demand of flash memory chips, benefiting key producers Samsung, Hynix Semiconductor and Toshiba.

Prices of computer memory chips are also set to rebound as PC makers are preparing to raise per-system chip content and chip makers are readying for price hikes after steep chip price decline.

The Nikkei business daily reported on Tuesday that Elpida Memory planned to raise prices of DRAM chips by about 10 percent as early as this month.

Hynix rose as much as 4.5 percent, Elpida rose 1.1 percent and Taiwan's Powerchip jumped 3.5 percent.

The report of Elpida's price rise plan points to similar moves by domestic (Korean) chip makers and strengthens sentiment toward the sector, said Daewoo Securities analyst James Song.

DRAM prices are expected to continue to recover this year.

(Additional reporting by Tim Kelly in TOKYO, Clare Jim in TAIPEI and Jungyoun Park in SEOUL; Editing by Muralikumar Anantharaman)