CHARLOTTE, N.C. -- US Airways ( LCC) reached an important milestone Wednesday, announcing a tentative contract agreement with its 3,300 maintenance and related employees.

The deal with the International Association of Machinists would move maintenance employees to a single contract, two-and-a-half years after the 2005 merger of US Airways with America West.

"This agreement provides stability and security for our members at a time when the airline industry is in turmoil," said IAM General Vice President Robert Roach Jr., in a prepared statement.

If ratified, the new contract would become amendable Dec. 21, 2011. It would cover about 800 former employees of America West, known as the west, as well as around 2,500 employees from the former US Airways, or the east.

Mechanics from both carriers would get wage and license premium increases, improved overtime rates, new shift premiums and participation in the IAM pension plan. Both groups were formerly covered by company-sponsored 401K plans.

"These unified agreements help fulfill an important goal of our merger, that is, to have each group of our represented employees working as one team with identical pay, benefits and work rules," said Al Hemenway, vice president of labor relations, in a prepared statement.

US Airways' progress on joint contracts for east and west workers has been slow. In 2006, the carrier signed a pact covering 7,500 airport and reservations agents, who are represented jointly by the Communications Workers of America and the Teamsters. However, there has been no such agreement with pilots, flight attendants or fleet service workers.

Pilots, in fact, are involved in a battle over seniority integration so divisive that an election, scheduled for March 20 through April 17, will determine whether the Air Line Pilots Association is ousted after 57 years.

The U.S. Airline Pilots Association, which is seeking to replace ALPA, staged a road show at Charlotte/Douglas International Airport Wednesday. Business was brisk, as several hundred pilots passed through an airport meeting room where USAPA leaders gathered.

Next week, USAPA plans a similar session in a hotel near the Phoenix airport. Although the group was created primarily to address the seniority concerns of pilots of the former US Airways, its leaders want to reach out to pilots who were with America West prior to the merger, as well.