SEOUL, July 31 (Reuters) - SK Innovation Co Ltd

, owner of South Korea's top refiner SK Energy, said

on Thursday it expects third-quarter refining margins to improve

after losses deepened in the second quarter.

"Sales and operating profit fell compared to the previous

quarter due to the difficult external environment such as global

economic uncertainty, tariff impact, and falling oil prices," SK

Innovation said in a statement.

"Further improvements in refining margins are expected in

the third quarter (and) easing tariff risks and increasing sales

volumes in Europe in the battery business will positively affect

earnings improvement," it said.

The company posted an operating loss of 418 billion won

($301.20 million) for April to June, compared with a loss of

45.8 billion won a year earlier.

The results were worse than an average analyst forecast for

a 140 billion won loss compiled by LSEG SmartEstimate.

($1=1,387.8000 won)