El Dorado refining margin, excluding finished product buy/sell activity, decreased to $12.74 per barrel compared to $13.71 per barrel sold during the 63 days we operated in the second quarter of 2011.
Retail segment contribution margin increased to $18.2 million in the second quarter 2012, versus $14.6 million in the second quarter 2011. Increases in fuel and merchandise same store sales and lower overall operating expenses contributed to improved performance as compared to second quarter 2011. Second quarter 2012 results were positively impacted by same store merchandise sales growth of 4.3 percent, which was supported by same store food service sales growth of 9.3 percent. In addition, same store fuel gallons sold increased 2.2 percent as declining fuel prices coincided with the peak driving season. The merchandise margin was 29.7 percent and the fuel margin was 18.2 cents per gallon for second quarter 2012.
At the conclusion of the second quarter 2012, the retail segment operated 374 locations, versus 390 locations at the end of the second quarter 2011.Marketing Segment Marketing segment contribution margin improved to $7.5 million in the second quarter 2012, versus $5.1 million in the second quarter 2011. The improved results were supported by an increase in total sales volumes of 4.5 percent, to 16,670 barrels per day, and the addition of bio-fuel sales. Reconciliation of GAAP to Non-GAAP Financial Measures Delek US reports its financial results in accordance with generally accepted accounting principles (GAAP). However, management believes that certain non-GAAP performance measures may provide users of financial information (i) increased transparency into the Company's operations; and (ii) additional meaningful comparisons between current results and results in prior operating periods. For these reasons, management is presenting certain adjustments to GAAP results in order to reflect the ongoing operations of the business. Management believes these measures will help investors better understand and evaluate the Company.