Atlanta-based Delta Air Lines reported a nearly $1.4 billion quarterly profit Tuesday, amid increased passenger traffic and strong holiday bookings.

The third quarter results also indicate that airlines have managed to keep fares high — with Delta president Ed Bastian saying in a written statement that the “revenue environment appears solid through the end of the year.”

Delta’s net income, which amounted to $1.59 per share, was up 31 percent from its results a year ago. It included an increase in the value of Delta’s fuel contracts, as well as expenditures for the airline’s aircraft replacements.

The higher profit came on $10.5 billion in operating revenue, up 6 percent from a year ago. Delta’s operating expense for the quarter amounted to nearly $9 billion, up 4 percent from a year ago.

Delta’s financial results also included a $40 million benefit from its new ownership stake in British carrier Virgin Atlantic.

And Delta also reported the first profit from the oil refinery it acquired last year.

Getting the oil refinery up and running with successful results has been more difficult than the airline expected. Delta said the Trainer refinery’s operations produced a $3 million profit in the September quarter, though results were pressured by a lower jet fuel premiums.