Interest expense in the first quarter of 2013 decreased to €13.1 million from €14.1 million in the comparative quarter of 2012, primarily due to lower debt levels associated with the Stendal mill in the first quarter of 2013.
We recorded a net derivative gain of €4.8 million, which includes a €0.3 million loss related to fixed price pulp swap contracts entered into in the fourth quarter of 2012 and an unrealized gain of approximately €5.1 million on the mark to market adjustment of our Stendal mill's interest rate derivative, compared to an unrealized derivative gain of €0.9 million in the same quarter of last year.
The noncontrolling shareholder's interest in each of the first quarters of 2013 and 2012 was €0.7 million.
In the first quarter of 2013, Operating EBITDA decreased to €24.3 million from €30.6 million in the first quarter of 2012. Operating EBITDA is defined as operating income (loss) plus depreciation and amortization and non-recurring capital asset impairment charges. Operating EBITDA has significant limitations as an analytical tool and should not be considered in isolation or as a substitute for our results as reported under GAAP. See page 9 of the financial tables included in the press release for a reconciliation of net income (loss) attributable to common shareholders to Operating EBITDA.We reported a net loss attributable to common shareholders of €0.4 million, or €0.01 per basic and diluted share, for the first quarter of 2013, which included a net non-cash unrealized gain of €4.7 million on the fixed price pulp swaps and Stendal interest rate derivative, partially offset by a non-cash charge for stock compensation of €0.3 million. In the first quarter of 2012, we reported net income attributable to common shareholders of €1.2 million, or €0.02 per basic and diluted share, which included a non-cash unrealized gain of €0.9 million on the Stendal interest rate derivative, offset by a non-cash charge for stock compensation of €0.9 million.