Minority freight workers at the Jacob K. Javits Convention Center are upset that the facility may be terminating a seniority list on which an increasing number of black and Latino employees had risen to be entitled to work assignments.

“We’re essentially going to be left with a white list,” an attorney for Local 807 of the Teamsters Union, Larry Cary, said.

Negotiations between Teamsters Local 807 and the state-owned convention center on Manhattan’s West Side collapsed and the deadline for the workers’ contract expired at midnight. According to Mr. Cary, the Javits Center has not legally agreed to continue observing the seniority list, on which a majority of senior workers are African American and Latino. The higher one rises on the list, the more frequently one is eligible to work on the larger trade shows at the Javits Center, which can significantly increase wages.

A spokesman for the Javits Center said: “The Convention Center Operating Corporation has agreed to keep the list in effect while we continue to bargain in good faith and hope to reach a mutually satisfactory agreement with Teamsters Local 807.” He said the list would not be terminated without prior notice being given to the Teamsters.

Mr. Cary called this “legal nonsense,” and added: “If they mean it, they should sign it.” Legally, he said, the seniority list expires at midnight.

Mr. Cary said the Teamsters would file an improper practices complaint with the Public Employees Relations Board. He said the union would also file a complaint with the federal monitor assigned to the Javits Center, Zachary Carter. Mr. Cary said the complaint would argue that the Javits Center’s legal termination of the list would have a disproportionate impact on blacks and Latinos.

Mr. Carter is charged with monitoring the terms of a consent decree in last year’s settlement of a racial discrimination suit brought by minority workers from a variety of occupations at the Javits Center; Javits Center and the state of New York paid $8.4 million to the workers and their lawyers as part of the settlement.

In 1996, the Javits management had set up a preference list that initially was 80% white but on which an increasing number of minorities have earned seniority. The Javits Center spokesman said they remained committed to reaching an agreement that would ensure a fair and equitable environment for the entire Javits workforce. The workers cannot strike because, as the Javits Center is a public benefit corporation created by New York State, they are subject to the Taylor Act.