Ericsson’s nearly $3 billion writedown related to its biggest acquisition will ratchet up the pressure on the key architect of the deal, Chief Executive Officer Borje Ekholm.

That’s the view of major shareholder and board member Cevian Capital AB, whose managing partner Christer Gardell told Bloomberg News that the under-fire CEO will need to justify why the Swedish maker of mobile networks spent almost 60 billion Swedish kronor ($5.5 billion) buying Vonage Holdings Corp. in 2022.

The impairment charge announced late on Wednesday is proof “of the massive destruction of shareholders’ capital,” Gardell said in emailed comments. The activist investor added that there will be “a lot of pressure now” on Ekholm and Chairman Jan Carlson “to create, not destroy, value for Ericsson’s owners.”

The comments follow news that Ericsson’s will book a charge in the third quarter for 50% of the total goodwill and other intangible assets attributed to Vonage. The company put the blame on higher interest rates and a slowdown in the US business it bought last year. The US-traded shares fell as much as 3.7% on the news.

The Swedish company noted a “significant drop in the market capitalization of Vonage’s publicly traded peers” in a disclosure of the charge. The firm also said it continues to believe, however, that the business “remains critical” to its enterprise strategy.

Activist investor Cevian has long been critical of the acquisition spearheaded by CEO Ekholm. Gardell’s co-partner, Lars Forberg, recently said in an interview that the deal “added nothing” from a strategic or financial perspective. Late last year, Cevian also called out Ericsson’s earnings as “disappointing” and urged the company to “drain the swamp of losses.”

For some analysts tracking the stock, the charge didn’t come as a surprise. “We, like many in the market, have been speculating about this event for a longer period, i.e. since the acquisition was completed,” said Daniel Djurberg, an analyst at Svenska Handelsbanken AB. “There is one less element of uncertainty.” Djurberg added that this writedown was a “healthy sign” and that he expected Ericsson to trade up in the coming months to year.

“We believe whispering expectations regarding a charge have been at least 20 billion, but of as much as 40 billion,” Predrag Savinonic, an analyst at Carnegie Investment Bank, said in a client note.

Also late on Wednesday, Ericsson reported preliminary net sales of 64.5 billion kronor for the third quarter, marking a 5.2% decline from the previous year. Network sales in North America were down 60% from a record a year earlier.

Ericsson, one of the world’s biggest providers of 5G networking equipment, has vowed to adjust prices and find ways to improve margins. The company, along with its peers, is struggling as the global market for networks and the gear that handles mobile communications is stagnating.

In an interview last month, Ekholm laid out a plan to create a portal with Deutsche Telekom AG for APIs, interfaces that allow different applications and systems to communicate with one another, through Vonage. Ekholm estimated at the time that the market was worth $20 billion and said the effort is critical to helping operators turn a profit from their network investments.

--With assistance from Lynn Doan.

(Updates with comments from Cevian’s managing partner, Carnegie analyst)