We will be happy to provide additional information about the changes and how we report our financial results during Q&A.
Turning to our financial results. In comparing the first quarter of 2012 to the fourth quarter of 2011, the story was weaker financial performance in QEP Energy, our E&P business, and slightly weaker financial performance in QEP Field Services, our gathering and processing business.
QEP Energy reported marginally higher equipment production, which included sequentially higher crude oil and NGL production but lower natural gas production, which is typical as we suspend completion activities in the winter in our Northern Region properties.
The production increase was offset by a 10% decrease in quarter-to-quarter net realized equipment prices. Field Services' first quarter results were marginally lower than the previous quarter primarily due to lower FA prices.
Our first quarter EBITDA was $345.7 million, which was $45 million or 11% lower than the fourth quarter of 2011, but up $40 million or 13% from the first quarter of 2011. QEP Energy contributed $261 million or 75% of our aggregate first quarter EBITDA, and QEP Field Services contributed $84 million or about 24%. QEP Energy's EBITDA was down about $40 million, while Field Services EBITDA was $3 million lower than the respective fourth quarter 2011 levels.
Factors driving our first quarter EBITDA include QEP Energy's production, which was 74.2 Bcfe in the quarter, slightly higher than the 73.9 Bcfe reported in the fourth quarter of 2011. The quarter's production was 12% higher than the 65.9 Bcfe produced in the first quarter of 2011. Of note, our gas lines were down 1 Bcf. Oil volumes were 1.2 million barrels, up 3% from the fourth quarter, and NGL volumes were also 1.2 million barrels, up 17% from the fourth quarter of 2011.
Combined oil and NGL volumes were 2.4 million barrels in the quarter compared to 1.1 million barrels of combined volumes in the first quarter of 2011. QEP Energy's net realized equivalent price, which includes the settlement of all of our combined derivatives, averaged $5.47 per Mcfe in the quarter, which was 10% lower than the $6.08 per Mcfe realized in the fourth quarter of '11 and $0.03 lower than the $5.50 per Mcfe realized in the first quarter of '11.