A group backed by activist hedge fund Starboard Value LP is offering about $9 billion for retailer Kohl’s Corp., according to people familiar with the matter.

The offer is led by Acacia Research Corp, which is run by Clifford Press and takes stakes in companies with an eye for ownership. Buying Kohl’s would be their largest acquisition to date. Acacia, backed financially by Starboard, now has a stake of less than 5% in the department store chain, the people said. The firm has in the past offered to buy Spok Holdings and Comtech Telecommunications Corp.

Private equity deals have boomed as investors built up huge cash reserves. By the middle of last year, the sector had amassed a record $3.3 trillion of unspent capital, including $1 trillion held by buyout funds, giving it significant firepower. Retailers have been in the takeover sights, with two of the U.K.’s biggest grocers, Asda and Morrison’s, purchased last year with private equity backing. Dow Jones earlier reported the planned acquisition. Kohl’s declined to comment on the offer.

The bid comes at a time when Kohl’s management is under fire from activist investor Macellum Advisors, which has been urging Kohl’s to make board changes or consider a sale in a letter to shareholders in recent weeks. The company said in response that Macellum has been “unwilling to constructively engage.”

The Menomonee Falls, Wisconsin-based retailer has had to contend with activist demands before. In March, Macellum was pressing to appoint a slew of executives to Kohl’s board after initially asking for control of the firm. Shares in Kohl’s have fallen nearly 20% since then.

The Acacia-led group offered $64 per share in cash, according to two people familiar with the matter, who asked not to be identified because the information was private. That’s a 37% premium to the department store chain’s closing price on Friday.

Jefferies Financial Group Inc. is advising Acacia on the purchase. Kohl’s declined to comment on the offer. Acacia shares declined 0.7% on Friday to close at $4.34, the lowest in more than a year. Kohl’s shares fell 2.6% to $46.84

Kohl’s management has sought to boost foot traffic and sales at its stores through partnerships with other retailers, most notably, e-commerce giant Amazon.com Inc. In 2020, it struck a deal with beauty products retailer Sephora to place shop-in-shops within the department-store chain. Kohl’s is also betting on athletic-leisure wear and said it sees sales in athletic wear being at least 30% of the business. Executives also often point to the fact that Kohl’s has advantages that other department-store chains don’t have by being mostly located in off-mall locations.

Engine Capital LP, which owns about 1% of Kohl’s outstanding shares, sent a letter to the board urging them to run a review of strategic alternatives, including a sale of the company, last month. Kohl’s was reported as a potential take “private candidate” in May last year.