SEOUL (Reuters) - South Korea's LG Display Co Ltd <034220.KS> said on Tuesday it reported a record fourth-quarter operating profit of 904.3 billion won ($778.33 million) due to a pickup in panel prices.

The world's biggest liquid crystal display (LDC) maker said the profit was caused by the upward trend of panel prices and a favorable foreign exchange rate.

"The upwards trend of panel prices is anticipated to continue thanks to the low inventory level in the industry and the trends towards large-size panels," Chief Financial Officer Don Kim said in a statement.

The price of television LCDs larger than 32 inches has been rising for 10 months, according to data provider WitsView last week.

Analysts said the rise was mainly due to supply-side factors such as rival Samsung Display Co Ltd's shutdown of an LCD fabrication plant last year, causing a tight supply-demand environment.

The company said its October-December operating profit of 904.3 billion won rose 1,392 percent from the same period previous year, beating a Thomson Reuters StarMine SmartEstimate of 845 billion won drawn from a survey of 27 analysts.

Revenue for the quarter rose 18 percent from a year earlier to 7.9 trillion won, LG said.

LG Display, which supplies screens for Apple Inc's <AAPL.O> iPhones and LG Electronics Inc's <066570.KS> TV sets, said earlier this month it was in talks with Samsung Electronics Co Ltd <005930.KS> about a supply agreement for TV panels.

(This story corrects percentage of on-year increase in lede, 6th graf.)

(Reporting by Joyce Lee; Editing by Chris Reese and David Gregorio)