American Airlines Group said Tuesday that it will raise pay rates by 4 percent for union-represented employees of US Airways and American that reach joint labor contracts.

Philadelphia's largest airline said nonunion employees, below the director level, will get the same 4 percent raise.

A year after the merger of US Airways and American, the airline's CEO Doug Parker said, "Taking this step just one year into our integration speaks volumes about just how well American is performing."

"We had been intending to make this announcement in late January 2015," Parker said, "but since we already know this year's results will be very strong, we decided instead to get the news out now and in advance of the New Year."

The wage increase is in addition to terms previously negotiated, and includes flight attendants from US Airways and American whose combined contract was recently finalized.

In a letter to employees, Parker said work groups that do not yet have ratified labor agreements, such as pilots, will get the higher pay once their contracts are approved.

American announced Tuesday that the pilot contract will be going to binding arbitration. Management and the Allied Pilots Association have not agreed to terms covering American and US Airways pilots.

"For those in work groups still negotiating joint contracts, we would like to reach joint agreements quickly so that all our team members are at industry leading wage levels soon," Parker said in his letter.

"For our flight attendants, this means the contract ratified just last week will now be improved (subject to APFA approval) by another 4 percentage points in pay, bringing their hourly rates 7 percent higher than the flight attendant pay rates at the other large network airlines (Delta or United)," Parker said.

"Lastly, for our non-contract [nonunion] team members below manager level, this increase is in addition to a previously announced 6 percent increase, bringing their total increase to 10 percent," Parker said in his letter.