By Se Young Lee

SEOUL (Reuters) - South Korea's LG Display Co Ltd said on Wednesday it will invest 1.99 trillion won ($1.75 billion) to boost capacity for flexible organic light-emitting diode (OLED) displays, its latest attempt to meet growing demand from mobile device makers.

OLED is widely expected to replace liquid crystal displays (LCD) for smartphones as the standard technology in a few years, and flexible displays can be curved or folded.

LG, the world's largest maker of LCDs, has been focusing on making OLED screens for televisions and is trailing behind Samsung Display Co Ltd, an unlisted unit of Samsung Electronics Co Ltd that is the largest maker of OLEDs for smartphones.

LG, in a regulatory filing, said it was building a new production line for small-to-medium sized flexible OLED screens in South Korea to address growing demand.

"A paradigm shift to OLED represents both a challenge and an opportunity for the display industry," LG Display Chief Executive Han Sang-beom said in a statement.

(Reporting by Se Young Lee; Editing by Richard Chang)