Shares of Levi Strauss & Co. slid after hours on Wednesday after the jeans maker tempered its full-year sales forecast, even as management said its core Levi’s brand was leading the way toward improvement and called out potential gains from its new partnership with Beyoncé.

Dockers, the khakis brand that was once a byword for business casual attire, has been put under a review for a potential sale by owner Levi Strauss. After they were introduced in 1986, Dockers became a mainstay of middle-aged men’s wardrobes. The brand “is credited with inventing Casual Fridays,” Levi Strauss has said.

The brand contributed about 5 percent of quarterly revenues as Dockers sales slackened by 15 percent from a year ago.