During the three months ended June 30, 2013, Rentech Nitrogen generated operating income of $34.0 million, compared to $41.6 million during the comparable period in the prior year. Operating income in the current period was reduced by lower gross profits as well as higher selling, general and administrative (SG&A) expenses and depreciation and amortization expenses attributable to the addition of the Pasadena Facility.
Adjusted EBITDA for the three months ended June 30, 2013 was $38.4 million, compared to $44.9 million in the corresponding period in 2012. Adjusted EBITDA excluding Partnership level expenses totaled $40.9 million for the current period. The East Dubuque Facility and the Pasadena Facility contributed $38.9 million and $2.0 million in EBITDA, respectively, during the three months ended June 30, 2013. Further explanation of Adjusted EBITDA, a non-GAAP financial measure, has been included below in this press release.
Gross margins for the three months ended June 30, 2013 were 38%, compared to 65% for the same period last year, primarily due to the addition of the Pasadena Facility, which realizes lower gross margins than the East Dubuque Facility, and the effects of allocating fixed costs to lower volumes of delivered products. Gross margins at the East Dubuque Facility were 61% for the current period, compared to 65% for the prior-year period. Gross margins at the Pasadena Facility were 6% for the current period, which reflected inventory write-downs and sales of products that were produced from higher-cost raw materials purchased earlier in the year. During the three months ended June 30, 2013, the Partnership incurred a write-down of ammonium sulfate inventories of approximately $1.8 million for product not shipped due to the reduced application from the prolonged wet weather.
SG&A expenses were $4.9 million for the three months ended June 30, 2013, compared to $3.9 million for the prior-year period. The increase was primarily due to the addition of $1.3 million of SG&A expenses from the Pasadena Facility, partially offset by a 28% decline in expenses at the East Dubuque Facility primarily due to lower unused credit facility fees, legal expenses and other professional fees.