UPDATE 1-Samsung SDI Q2 profit rises on battery, TV demand

(Adds details, shares)

SEOUL, July 21 (Reuters) - Samsung SDI (006400.KS) reported on Tuesday a 33 percent rise in quarterly operating profit, beating forecasts, helped by strength in rechargeable batteries and improving demand for plasma screens used in televisions.

It expected demand for lithium ion batteries to grow 41 percent in the second half from the first and the market's oversupply to ease, thanks to robust sales of smartphones and expected demand for notebook PCs in the back-to-school season.

Global plasma panel demand is likely to jump 48 percent in the second half on the booming Chinese flat TV market and growing U.S. demand for digital TV sets, Samsung SDI said in a statement.

After suffering a steep operating loss in the first quarter, the South Korean company is recovering from the impact of the global downturn helped by restructuring efforts.

Samsung SDI posted a 48.8 billion won ($38.95 million) operating profit on a consolidated basis in the second quarter, beating a consensus forecast of 14.3 billion won from Reuters Estimates.

The figure compared with a 36.6 billion won profit a year earlier and a 76 billion won operating loss in the January-March quarter.

Second-quarter net profit came at 58 billion won, also larger than a forecast of 30.1 billion won.

Consolidated quarterly sales came at 1.19 trillion won, down 6 percent from a year earlier.

Samsung SDI spun off its mobile display unit last year into a 50-50 joint venture with Samsung Electronics (005930.KS) and has since been focusing on lithium ion batteries.

It trails Japan's Sanyo Electric 6764.T in rechargeable batteries and plans to expand its business into larger batteries and energy storage systems.

Its plasma display panel business, stuck in a tough competition with liquid crystal display (LCD) technology, has been plagued by falling screen prices but is improving on growing sales and a focus on larger, high-definition screens.

Samsung SDI shares fell 1.9 percent to 105,500 won by 0514 GMT, lagging the wider market's .KS11 0.5 percent rise. ($1=1252.7 Won) (Reporting by Rhee So-eui; Editing by Jonathan Hopfner)