Starting with the financials. The adjusted net income for the quarter was $314 million or $1.75 per share diluted, that's an increase of 31% compared to the first quarter of last year. Our only adjustment was for unrealized commodity derivative losses due to strong oil prices.
GAAP net income was $263 million or $1.47 per share diluted. Quarterly revenues were almost $1.2 billion, a 30% increase over the first quarter of last year. Crude oil and liquids represented nearly half of our sales volumes and combined with strong prices accounted for over 80% of our revenue for the first quarter.
Our sales volumes were a record 243,000 barrels of oil equivalent per day, up 10,000 barrels of oil equivalent from the fourth quarter of last year and up 13% from the first quarter of 2011. Our sales exceeded quarterly guidance range that we issued earlier this year, and essentially all of the increased production was from crude oil and liquids sales.
The outperformance was driven by exceptional operating performance at Aseng, which completed its first quarter production, as well as continued growth from the horizontal program in the DJ Basin and the deferral of some maintenance downtime in our non-operated Alba facilities from the first to the second quarter. The good news is that, that Alba maintenance has now been completed, and the field is back up.47% of the total sales volumes for the quarter were liquids. That's up from 40% in the fourth quarter of last year. Our U.S. sales volumes were 131,000 barrels of oil equivalent per day with 45% being liquids. Compared to the first quarter last year, U.S. sales volumes increased 15%, largely driven by increases from Wattenberg and the addition of the Marcellus Joint Venture. The DJ Basin production totaled 73,000 barrels of oil equivalent per day, with oil representing 39% of the volume mix, and Natural Gas Liquids representing 17% of the total volumes. Read the rest of this transcript for free on seekingalpha.com