Activist investor Elliott Management has amassed a stake of more than $1 billion in Lululemon Athletica and is lining up a potential CEO candidate as it pushes to revive the struggling athletic apparel ⁠retailer, a source told Reuters on Wednesday.

Elliott has been working closely for months with veteran retail executive Jane Nielsen, former chief ⁠financial officer and chief operations officer at Ralph Lauren, and views her as a potential CEO candidate, the source added.

The hedge fund is now one of Lululemon’s biggest investors, with the move coming ‍amid a ‌busy year for Elliott that already includes a recent investment in PepsiCo and ⁠an earlier proxy fight at Phillips66.

The ‌Wall Street Journal first reported the stake. Elliott and Lululemon did ‌not immediately respond to Reuters’ requests for comment.

Last week, Lululemon said CEO Calvin McDonald would step down in January after seven years in the role, without naming a successor. Its share price rose after news of McDonald’s impending departure but ‍has dropped about 60% from its peak two years ago.

The company, valued at $25 billion, now likely faces an expensive and drawn-out board dispute over the position of ‌CEO. Its founder ⁠and ​largest shareholder, Chip Wilson, has also called for an urgent CEO ⁠search, ​led by new, independent directors with deep company knowledge to restore a product-first focus.

Wilson, who has previously courted criticism by saying some women’s body shapes “just actually don’t work” ​with Lululemon yoga pants, has publicly blamed McDonald and the board for the company’s lagging share price.

Known for its high-priced leggings ⁠and athleisure wear, Lululemon has ceded market share ⁠to newer brands such as Alo Yoga and to lower-cost private-label lookalikes, with executives voicing disappointment with product execution.