POSCO <005490.KS>, the world's third-biggest steelmaker and backed by billionaire investor Warren Buffett, posted a 5.9 percent rise in profit for the third quarter, meeting consensus, thanks to higher sales volume and prices.

The South Korean company, which trails ArcelorMittal and Baosteel <600019.SS>, said on Friday its July-September operating profit was 1.09 trillion won ($951.8 million), compared with an average 1.15 trillion won forecast from analysts, according to Thomson Reuters I/B/E/S.

The profit compared with 1.03 trillion won a year ago, but was down from 1.5 trillion won in the previous quarter because of higher raw materials costs, POSCO said.

Shares in POSCO, in which Buffett's Berkshire Hathaway owns an around 5 percent stake, have fallen 26 percent this year, compared with a 10 percent drop in the broader market <.KS11>. ($1 = 1145.200 Korean Won)

(Reporting by Hyunjoo Jin; Editing by Muralikumar Anantharaman and Jonathan Hopfner)