Amazon.com Inc. employees in Alabama voted not to unionize, handing the tech giant a victory in its biggest battle yet against labor-organizing efforts that fueled national debate over working conditions at one of the nation’s largest employers.

An estimated 71% of the Bessemer, Ala., warehouse workers who cast ballots voted against joining the Retail, Wholesale and Department Store Union, according to the National Labor Relations Board, which on Friday finished counting all the votes that weren’t challenged. The federal agency has yet to certify the results but noted that the challenged ballots aren’t enough to exceed the vote margin against unionization.

The National Labor Relations Board has finished counting all votes that weren’t challenged by either side, and the number of votes against a union exceeds 1,608, the total needed to reach a majority of the 3,215 mail-in ballots workers submitted. The NLRB hasn’t declared an official winner.

Shares of Amazon rose more than 1% to the highest level in two months.

The Bessemer facility employs less than 1% of the roughly 950,000 Amazon employees in the U.S., but the vote emerged as a watershed moment for a company that hired faster than almost any private corporation in history last year.