Starbucks workers at three more Buffalo-area stores file for union elections.

One day before ballots were scheduled to go out to workers at three Buffalo-area Starbucks in a vote on unionization, workers at three other stores in the area filed petitions with federal regulators on Tuesday requesting elections as well.

The coming vote is significant because none of the nearly 9,000 corporate-owned Starbucks stores in the United States are unionized.

On Monday, Starbucks filed a motion to stay the mailing of ballots while it appeals a ruling by a regional official of the National Labor Relations Board setting up separate votes at the three locations where workers initially filed for elections. The company wants all of the roughly 20 Buffalo-area stores to vote in a single election, an approach that typically favors employers.

The first three stores filed for union elections in late August, and Starbucks dispatched managers and more senior company officials to the area from out of state in the weeks that followed in what it said was an effort to fix operational issues.

The union has complained that the out-of-town officials are unlawfully intimidating and surveilling workers and filed an unfair labor practice charge making this accusation last week. The union also contends that Starbucks transferred in or hired a number of additional employees at two of the three stores to dilute union support.

The so-called packing of a workplace before a union election is unlawful if bringing in new workers serves no legitimate business purpose and if the employer has reason to believe that the new workers will oppose a union. Starbucks has said the additional workers are needed to deal with staffing shortages.

The Starbucks workers who support unionizing are seeking to join Workers United, an affiliate of the Service Employees International Union. The union says there are 31 to 41 eligible employees at each of the three locations filing the new petitions. It is seeking elections at each of them on Nov. 30.

Starbucks has maintained that individual stores should not hold separate elections because its employees can work at multiple locations and because it largely manages stores in a single area as a group rather than at a store level.

“We believe all of our partners in this Buffalo market deserve the right to vote,” Reggie Borges, a company spokesman, said Tuesday. “Today’s announcement that partners in three additional Buffalo stores are filing to vote underscores our position that partners throughout the market should have a voice in this important decision.”