* Q4 operating profit 3.0 trln won vs 3.4 trln won fcast
* Sharp fall in chips, LCD biggest concern
* Solid smartphone sales, mobile chips to lift Q1 profit
* Samsung shares up 0.3 pct vs 0.1 pct fall in KOSPI
SEOUL, Jan 28 (Reuters) - Samsung Electronics Co (005930.KS), the world's top memory chipmaker, reported its weakest profit in six quarters, as muted demand for televisions and computers hit prices of its mainstay chips and flat screens.
The world's top maker of flat screens and televisions expected on Friday intensifying price competition in major consumer electronics products this year and a price decline in key components such as chips and flat-screen displays.
Emerging as a credible challenger to Apple (AAPL.O) in mobile devices, the South Korean firm plans to spend 23 trillion won ($20.6 billion) this year to upgrade or build plants producing chips and flat screens to expand its market share.
Samsung is set to show a modest rebound in earnings this year as it rolls out new smartphones and tablets, which will counter the impact of a slowdown in components such as chips and flat screens.
Samsung, also the world's No.2 maker of mobile phones, reported on Friday a 3.0 trillion won ($2.7 billion) operating profit for October-December, missing a consensus forecast for a 3.4 trillion won profit polled by Thomson Reuters I/B/E/S.
SPECIAL REPORT on Samsung: r.reuters.com/cuz67r
Analysts view on results [ID:nTOE70P07Z]
Apple, Nokia results [ID:nN18171874] [ID;nLDE70Q0QK]
Earlier this month, Samsung said it would post an operating profit of between 2.8 trillion won and 3.2 trillion won. [ID:nL3E7C70AH]
The result compares with a 4.9 trillion won profit in the preceding quarter and 3.4 trillion won a year earlier.
Samsung trails Nokia (NOK1V.HE) in mobile phones and competes with Sony Corp (6758.T) and LG Electronics Inc (066570.KS) in TVs and Toshiba (6502.T) and Hynix (000660.KS) in semiconductor.
Shares in Samsung, whose $145 billion market value is now larger than Intel's (INTC.O) and Hewlett Packard's, have risen by a third to record highs in the last three months to record highs, beating a 10 percent gain in the KOSPI .KS11. ($1=1114.3 Won) (Editing by Anshuman Daga)