NEW YORK (AP) — Fitch Ratings on Monday raised US Airways' ratings and assigned the airline a "positive" outlook after its record financial performance in 2012.

The upgrade didn't take into account potential improvement from the company's pending merger with American Airlines, Fitch said. The agency added that it considered the deal's benefits in the outlook.

Fitch raised the default ratings for US Airways Group Inc. and its airline operating subsidiary to "B+" from "B-," which is still below investment-grade. Fitch noted that US Airways reported record profit and revenue in 2012 despite a lackluster economy and volatile fuel prices.

Fitch said US Airways' debt levels remain high, with debt and capital leases of $4.8 billion at year end, an increase of $227 million from a year earlier.

Monday's ratings changes affect $1.1 billion in term loans and $179 million in convertible notes.

Fitch said the merger with American, which is subject to regulatory approval, would boost US Airways' creditworthiness, but potential benefits will occur "over the longer term."

US Airways shares fell 30 cents to close at $16.67. They have gained more than 23 percent so far this year.