NEW YORK — OAO Severstal’s North American operations posted lower financial results in the fourth quarter as an unplanned outage at its Dearborn, Mich., mill reduced output, the Russian steelmaker said.

The Moscow-based company’s Severstal International unit, which includes its Dearborn and Columbus, Miss., steel works, recorded revenue of $810 million in the fourth quarter, down 11 percent from $910 million in the third quarter, while earnings before interest, taxes, depreciation and amortization (Ebitda) per tonne fell to $6 from $16 in the same comparison.

Severstal partially attributed the weaker results to a November pipe explosion at the Dearborn mill, which resulted in a two-week outage (amm.com, Nov. 28). Lower realized steel prices, a decrease in selling volumes and a write-off related to provisions against receivables at Severstal’s coke production venture, Mountain State Carbon LLC, also contributed to the lower results, it said.

For all of 2012, Severstal International logged a net loss of $258.8 million on revenue of $3.9 billion.