(Adds details on the quarter, context and share price)
* Q4 operating profit 785 bln won vs 780 bln won forecast
* DRAM shipments down 13 q/q due to China plant fire
* Shares end down 1.8 pct prior to earnings announcement
SEOUL, Jan 28 (Reuters) - South Korea's SK Hynix Inc ended its two consecutive quarters of record high earnings on Tuesday, as a rally in computer memory chip prices have started to ease and production remained tight following a fire at its plant in China.
The Apple Inc supplier is bracing for a tougher year after posting record profits in 2013, as the PC industry continues to shrink and growth in the booming mobile devices market slows.
Apple missed Wall Street's target for iPhone sales over the crucial holiday shopping season and offered a weaker-than-expected forecast for this quarter, underscoring challenges smartphone makers are facing as a result of high-end market saturation in many advanced economies.
The world's second-biggest memory chipmaker reported 785 billion won ($724 million) in October-December operating profit, broadly in line with analysts' consensus forecast of 780 billion expected by Thomson Reuters I/B/E/S.
The result compares with a 55 billion won profit a year ago and a record 1.16 trillion won profit in the previous quarter.
Hynix is hoping a gradual recovery in production from the damaged plant in Wuxi, which manufactured 15 percent of global DRAM chips before the blaze in September, will help cushion the impact of weakening chip prices and win back market share from rivals.
It competes with market leader Samsung Electronics Co Ltd , Japan's Toshiba Corp and U.S.-based Micron Technology Inc.
Hynix said shipments of dynamic random access memory (DRAM) chips fell 13 percent in the fourth quarter from the previous quarter due to reduced output from a China plant, outweighing a 1 percent increase in prices sparked by concerns over tight supply, even as the PC market continued to shrink.
Worldwide PC shipments fell 10 percent last year after declining seven consecutive quarters as manufacturers could not stop consumers opting for smartphones and tablets instead, according to researcher IDC.
Contract prices of DRAM chips, widely used in computers, dropped 3 percent in the first half of January, according to price tracker DRAMeXchange.com.
Shares of Hynix closed down 1.8 percent on Monday prior to the earnings announcement, compared with a 1.6 percent decline in the benchmark index. The stock has gained 8 percent over the past three months, beating a 5 percent drop in the wider market. (Reporting by Miyoung Kim; Editing by Bernard Orr)