Pilots at Spirit Airlines went on strike on Saturday after U.S.-mediated contract talks failed to reach an agreement, a small-carrier stalemate that could influence workers at bigger carriers.

The strike at privately held Spirit was the first notable job action at a U.S. passenger airline since Northwest Airlines mechanics walked off the job in 2005.

All Spirit flights for Saturday were canceled. The Miramar, Florida, discount airline carries less than 1 percent of U.S. air-passenger traffic.

Airline unions across the industry are watching the Spirit talks closely as many groups are in active contract negotiations or getting ready to begin talks.

Spirit's 430 pilots are represented by the Air Line Pilots Association (ALPA), which could not bridge differences with management over pay, benefits and scheduling.

We are frustrated and disappointed that our pilots have turned down an over 30 percent increase at a cost of over $70 million over five years while disrupting thousands of our customers and jeopardizing the livelihoods of our over 2,000 employees, Spirit Airlines CEO Ben Baldanza said in a news release.

ALPA, the largest pilots union in the United States, said in a statement that the Spirit pilots went on strike after numerous attempts to find a middle ground with management. It said pilots at Spirit have been working at below-market compensation rates and work rules for years.

The airline has worked out agreements with a variety of U.S. and foreign airlines to accommodate stranded passengers, Baldanza told The Wall Street Journal in an interview on Saturday. He declined to name the airlines.

Baldanza said his goal was to get the airline flying again as soon as possible, but he could not predict when.

One industry observer said the strike comes at a tricky time for consumers.

With planes so crowded lately, it's going to be hard for passengers to find seats on other carriers, George Hobica, president of Airfarewatchdog, told Reuters via email.

In advance of the job action, Spirit pre-canceled a number of flights for this weekend. About 18,000 passengers originally were booked to fly Saturday, The Wall Street Journal reported.

With U.S. airlines on stronger financial footing, unions are eager to recapture pay and benefits lost during the industry's drastic restructuring from 2002-07. Spirit is profitable, helped partly by low labor costs.

Airline strikes, due to the importance of the industry to U.S. commerce, are permitted under federal law only after mediated talks fail to produce an agreement.

(Reporting by John Crawley in Washington, Karen Jacobs in Atlanta and Matthew Lewis in Chicago; Editing by Eric Beech)