In addition, there are other related cases involving the union and Trump Plaza still pending, Moore-Duncan said.

If the petition to decertify the UAW as the dealers' union had moved forward, there could have been a new election in which dealers voted again on whether to join the union.

Trump Plaza has argued for a new election, claiming the original one in March 2007 was tainted by a media event held days prior to the vote, although the federal labor board still certified the results in May 2008. Dealers voted by a 68 percent majority in favor of representation.

While the casino's latest appeal is tied up in federal court, Trump Plaza management has refused to bargain at all.

Trump Entertainment Resorts Inc., which owns Trump Plaza, has said it expects to win in court. The case was first filed in September 2008.

The court could side with the casino or uphold the National Labor Relations Board's ruling requiring the casino to bargain.

Trump Plaza dealers who support the Detroit-based UAW said Monday that the federal labor board made the right decision to dismiss the decertification petition.

"Sure, people are frustrated," said Absecon resident Marybeth Litchholt, a dealer at the casino for more than 22 years. "They are frustrated with Trump Plaza because management disrespected our vote and won't come to the bargaining table. There's an easy way to fix this: Let's sit down together and bargain."

Litchholt said the majority of dealers at the casino still want union representation.

At least 30 percent of the 483 dealers at Trump Plaza had to sign the decertification petition. It's unclear how many did, although the UAW believes they are mostly dealers who had voted against the union two years ago.

Moore-Duncan said another petition could be put forward in the future and include the same signatures, but the board would again look at how timely it is and the amount of interest shown.

Also on Monday, Trump Entertainment CEO Mark Juliano sent a memo to employees saying it was not behind media advertisements spotlighting the decertification effort by some dealers.

"We want you to know that our organization had no involvement or prior notification of the advertisements," Juliano wrote. "As part of their ongoing media campaign against the UAW, Harrah's elected to include the Plaza dealers decertification petition in their advertisements."

"Throughout this entire process, it has not been our intention to attack any dealers who have chosen to support the union," Juliano continued.

The UAW is locked in a public campaign against Harrah's Entertainment Inc., which owns Bally's Atlantic City and Caesars Atlantic City, two casinos where dealers are represented by the union but have been unable to secure contracts. The UAW has lobbed its own ads against Harrah's, telling people not to visit either gaming hall.

Harrah's spokeswoman Marybel Batjer declined to comment Monday.

The UAW also represents dealers at Tropicana Casino and Resort, where dealers are still negotiating with management.