Workers at Tyson Foods in Buffalo rejected a Teamsters union campaign by 62 percent in voting Thursday and Friday.
The Teamsters had sought to unionize 373 full- and part-time production workers at the plant in Buffalo's warehouse district.
Tyson's site at 665 Perry St. processes deli meats and franks, sold under the Russer brand and other names.
Workers voted 213 to 126 against joining the union, according to the National Labor Relations Board.
Officials of Teamsters Local 449 couldn't be reached for comment. The union has seven days to file objections with the labor board before the vote is finalized.
The vote marked the third time in five years that union drives have foundered at the plant. Workers previously voted against joining the Steelworkers in 2003 and the United Food & Commercial Workers in 1999.
"We appreciate our team members' decision to keep the plant union-free," Tyson spokesman Gary Mickelson said in an e-mail interview. Management keeps an open-door policy that encourages communication with workers, he said.
Tyson, based in Springdale, Ark., acquired the former Russer plant in 2001. Including non-union workers, it employs 475 people.