Wal-Mart, the world's biggest retailer, has won another round in its struggle to keep its U.S. workforce from joining labor unions.

Friday, workers voted 17-1 to reject union representation at a tire store operated by Wal-Mart in Loveland, in the western state of Colorado.

Wal-Mart recently said it will close a Canadian store that voted for union representation and fire the store's 190 member staff.

Earlier, the company eliminated meat-cutting jobs from its entire grocery operation after some butchers voted to bring in a union.

Wal-Mart has 1.2 million employees who operate 3,500 stores in the United States, Canada, China, Mexico, Brazil, Germany, the United Kingdom, and South Korea.

The United Food & Commercial Workers Union says it will continue efforts to unionize Wal-Mart.