The International Brotherhood of Teamsters, which represents more than 10,000 Costco workers, authorized a nationwide strike to occur in February.

With a master agreement with the Teamsters set to expire in 10 days, affecting 18,000 of the retailer's workers, hundreds last week held practice pickets.

The more than 18,000 Costco Wholesale employees represented by the Teamsters union voted overwhelmingly to authorize a nationwide strike should they not reach a new labor agreement by the end of the month.