NEW YORK (Reuters) - The board of the union representing US Airways pilots on Friday unanimously backed a key labor proposal made by American Airline pilots, a move that helps advance a potential merger of the two carriers.

The US Airline Pilots Association said its board voted to recommend that its 5,000 members back the measure, which governs how the two unions would be integrated if the airlines were to combine.

US Airways formally proposed a merger in November and American Airlines parent AMR Corp is expected to consider it at a board meeting next week.

(Reporting by Alwyn Scott)