Flight attendants at Minneapolis-based Compass Airlines, a feeder carrier for Delta Air Lines, took another step toward trying to get contract issues resolved with owner Trans States Holdings and warned they were willing to strike if an agreement isn’t reached.

Workers at the Delta Connections carrier have been trying to reach an agreement with St. Louis-based Trans States since 2010. Compass provides about 190 daily flights to more than 50 Delta destinations. The airline operates flights from Delta’s hubs in Minneapolis and Detroit.

The Association of Flight Attendants – CWA, which represents the 450 flight attendants at Compass — said the workers are willing to strike if a new agreement on wages, better working conditions and benefits is not negotiated. They first voted to authorize a strike in October. Both sides have been in mediation since October 2011.

The workers are seeking a “proffer of arbitration” from the National Mediation Board. If granted, it would give the two parties the opportunity to have remaining issues settled by binding arbitration. If either party declines to accept the proffer, the NMB could declare efforts to reach a contract have failed and release them from mediation, which would set the stage for a possible strike after a cooling-off period.

There was no immediate reaction to the latest developments from Trans States.

“Compass flight attendants are determined to reach an agreement,” the union said in a statement Thursday. “We are committed to the success of our airline and our contributions continue to make the company a top-of-the-industry performer.” But the union warned that “if management continues to choose obstruction over cooperation” workers will resort to “CHAOS” – a strike strategy that stands for “Create Havoc Around Our System.”

Compass was a regional carrier for Northwest Airlines, which Delta acquired in 2008. Delta sold Compass to Trans States in 2010, though Compass continues to operate as a regional carrier for Delta.