US Airways said net income doubled in the fourth quarter as its planes were fuller and it made more money off each passenger.

The airline on Wednesday reported a profit of $37 million, or 22 cents per share, compared with $18 million, or 11 cents per share a year ago. Excluding special items, net income was 26 cents per share, 7 cents higher than analyst forecasts, according to FactSet.

Revenue rose 3.9 percent to $3.28 billon.

Per-seat passenger revenue — a key performance indicator for airlines — rose 2.2 percent. Occupancy rose 2 percentage points to 83.9 percent.

US Airways is in merger talks with American Airlines, but didn’t address the talks in its earnings release.

Some have assumed that as the fifth-biggest U.S. airline, US Airways needs the American merger to survive. J.P. Morgan analyst Jamie Baker wrote in a note to investors Wednesday that he disagrees.

“With 2012 margins just shy of Delta while topping those of Southwest and United, we find investor stand-alone pessimism to be significantly misplaced,” he wrote.

Shares of Tempe-based US Airways Group Inc. rose 30 cents, or 2 percent, to $15.15 in morning trading.