Expedia reported a net loss of $3.3 million for the first quarter of the year compared to earnings of $52 million a year earlier. But quarterly revenue rose 12 percent to $816.5 million, mainly due to an increase in hotel room nights.

Room nights grew 24 percent year-over-year primarily due to 37 percent year-over-year growth in room nights at Hotels.com. Average daily room rates were flat. On the air side, average airfares grew 7 percent year-over year; Expedia sold 5 percent more air tickets mainly because a dispute last year with American Airlines meant Expedia didn’t sell American tickets during the first quarter 2011.

Overall, domestic bookings increased 16 percent and international bookings increased 14 percent for the first quarter of 2012. International bookings totaled $3.3 billion for the first quarter of 2012, accounting for 39 percent of worldwide bookings, which was similar to last year.

Other revenues, such as car rentals, advertising revenue and corporate travel fees, increased 15 percent in the first quarter. The growth in room nights was partially offset by a decrease in revenue per room night and revenue per ticket. Domestic revenue increased 11 percent and international revenue increased 14 percent.