Apple store employees in a Baltimore suburb voted to unionise by a nearly 2-to-1 margin on Saturday, a union said, joining a growing push across US retail, service and tech industries to organise for greater workplace protections.
The vote could not immediately be confirmed with the National Labour Relations Board, which would have to certify the outcome.
An NLRB spokesperson referred initial queries about the vote to the board's regional office, which was closed late Saturday.
Apple declined to comment on Saturday's development, company spokesperson Josh Lipton told The Associated Press by phone.
Union organising in a variety of fields has gained momentum recently after decades of decline in US union membership.
Organisers have worked to establish unions at companies including Amazon, Starbucks, Google parent company Alphabet and outdoors retailer REI.
The International Association of Machinists and Aerospace Workers and the Apple employees who wanted to join said they sent Apple CEO Tim Cook notice last month that they were seeking to form a union.
The statement said their driving motivation was to seek “rights we do not currently have”. It added that the workers recently organised in the Coalition of Organised Retail Employees (CORE).
“I applaud the courage displayed by CORE members at the Apple store in Towson for achieving this historic victory,” said IAM International President Robert Martinez Jr. in the statement.
“They made a huge sacrifice for thousands of Apple employees across the nation who had all eyes on this election.” Martinez called on Apple to respect the election results and to let the unionising employees fast-track efforts to secure a contract at the Towson location.
It remained unclear what steps would follow the vote in Towson. Labour experts say it's common for employers to drag out the bargaining process in an effort to take the momentum out of union campaigns.
The IAM bills itself as one of the largest and most diverse industrial trade unions in North America, representing approximately 600,000 active and retired members in the aerospace, defence, airlines, railroad, transit, healthcare, automotive, and other industries.
The Apple store unionisation comes against a backdrop of other labour organising nationwide — some of them rebuffed.
Amazon workers at a warehouse in New York City voted to unionize in April, the first successful US organising effort in the retail giant's history.
However, workers at another Amazon warehouse on Staten Island overwhelmingly rejected a union bid last month.
Meanwhile, Starbucks workers at dozens of US stores have voted to unionise in recent months, after two of the coffee chain's stores in Buffalo, New York, voted to unionise late last year.
Many unionisation efforts have been led by young workers in their 20s and even in their teens.
A group of Google engineers and other workers formed the Alphabet Workers Union last year, which represents around 800 Google employees and is run by five people who are under 35.