Privately owned by the descendants of the family of founder Levi Strauss, the firm is still the world’s biggest denim brand ahead of VF Corp’s Wrangler’s and Lee labels. But it has been in decline for years as competition has mounted from luxury, discount and mass fashion brands, compounded by the rising popularity of sportswear as a casual alternative to jeans.

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James Curleigh, president of the Levi’s brand, said Levi’s is seeking to connect with younger consumers by adjusting its designs to their tastes, by adding more stretch and tapering legs as well as tapping into the music scene, including teaming up with singer Alicia Keys for the launch of its women’s collection in July.

“Our women’s business has never been stronger than it is right now,” Curleigh told Reuters at the World Retail Congress. “It is back. It’s in growth mode. No-one traded their entire wardrobe for yoga pants.

“We know that if someone goes into a pair of Levi’s they tend to stay with us for a really long time, but we have to make that initial reconnection.”

Total sales of jeans in the United States fell 5 percent in the year ending May 2015, data from information group NPD showed. But they increased 2 percent among the group of 18-34 year-old consumers dubbed millennials by marketers.

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The size of the global jeans market could grow to almost $143 billion in 2019 from nearly $102 billion in 2014, data firm Euromonitor predicts, with most growth coming from developing markets. The global sportswear market is almost three times as big.

As it seeks a bigger market share, Levi’s hopes to win customers by promoting the durability of its products. It is also responding to growing consumer interest in environmental issues by working on ways to cut water use, improve recycling techniques and encourage the repair and resale of old jeans as vintage styles become fashionable again.

“The best that you ever look in a piece of fast fashion is the first time you wear it. It has this sort of half-life,” Curleigh said. “…What we’re promising with a pair of Levi’s, or anything from Levi’s, is the best you’re going to look is one, two, three, five, 10 years in the future.”

That sentiment chimes with the brand’s “Live in Levi’s” slogan and a site launched in 2014 to collect fan’s stories, pictures and videos about their favorite jeans.

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Levi’s sales fell 6 percent to $1.012 billion in the quarter to May 31, although they rose 1 percent on a constant currency basis, helped by growth from its stores in Europe and Asia.

Noting that denim only makes up about 6 percent of an average wardrobe, Curleigh said Levi’s is selling more belts, tops, footwear, socks and underwear, which still only make up 20 percent of its sales but are performing better than jeans.

“Every one of our categories outside denim is growing faster than denim but we are still growing denim so ‘protect the core, expand for more’ is working,” he said