DALLAS ( TheStreet) -- The Transport Workers Union asked Thursday to be released from mediation at American ( AMR), a week after the carrier's flight attendants said they will make a similar request. The TWU request came even though both the union and the airline say talks are progressing. In combination with the anticipated request by the Association of Professional Flight Attendants, it promised to increase the focus on labor issues at American as the carrier continues to negotiate its first contracts since a round of concessions in 2003, when bankruptcy was looming. "While we have reached tentative agreements for some workers at American Eagle and significant progress has been made in recent days for fleet service workers at American, overall AMR has not sufficiently demonstrated that they value the sacrifices and hard work of our members," said John Conley, the union's air transport director, in a prepared statement. "We have been at the bargaining table for years and will continue to work toward agreements, but it's time that we moved the settlement process to the next step," Conley said. "We are prepared to negotiate, but we will not stand by as AMR executives are awarded large bonuses and our members are left with pennies." The TWU is the carrier's largest union, with 28,000 members in 11 bargaining units at American and American Eagle. The current round of negotiations began in 2007. American said it was disappointed by the request. "We just concluded five days of talks with the TWU Fleet negotiating committee in Washington, D.C., where the teams made significant progress, reaching tentative agreements on six additional articles," said spokeswoman Missy Latham, in a prepared statement. "This brings the total articles agreed upon in the fleet contract to 87%, with six articles remaining" "American continues to believe any talk of 'release' at this time is premature and thinks that actions such as these can be detrimental to the process," she said, noting that later today the NMB is expected to schedule the next negotiating session with TWU fleet service negotiators. Technically, the TWU presented a letter to the National Mediation Board, asking to be released from mediation. That triggers a comment period of 10 days to two weeks. If a release is granted, it would be followed by a 30-day countdown period until the union would be free to strike. But the board could also propose arbitration or further mediation. Even after the 30-day period, President Obama could intercede to prevent a strike.