(Reuters) -Activist-investor Carl Icahn sued the board of directors at genetic testing company Illumina (NASDAQ:ILMN) and accused them of breaching their fiduciary duties, according to a sealed copy of the complaint.
The publicly available version of the complaint did not contain further details, but Icahn told the 13D Monitor Active-Passive Investor Summit in New York on Tuesday that the lawsuit pertained to Illumina completing its acquisition of cancer diagnostic test maker Grail.
Earlier this month the EU ordered Illumina to sell Grail.
The purchase of Grail had been a centerpiece of Icahn's successful proxy fight at Illumina earlier this year, when he pushed the company to unwind the deal, arguing it cost investors billions.
Illumina said it is reviewing the complaint, but did not immediately respond to Reuters requests for additional comment.
Icahn, 87, said on Wednesday that he has never found it necessary to sue a company's board of directors until now.
"I have done so today in light of, among other things, the board's unconscionable and egregious actions relating to closing the acquisition of Grail without regulatory approval, thus putting Illumina, a great company, in harm’s way," he said.
Illumina's stock price has tumbled 36% since January, and the board replaced the CEO soon after Icahn won one board seat.
The gene-sequencing machine maker had repurchased Grail in 2021 despite opposition from U.S. and European antitrust regulators.
Last week, Illumina said it would divest Grail in 12 months, according to the terms of the European Commission's order, if it does not win its challenge in court.
San Diego-based Illumina in September named former Agilent Technologies (NYSE:A) executive Jacob Thaysen as its CEO.
"I continue to believe in the company's long-term potential and I have full faith in Illumina's new CEO, and its employees," Icahn said in the statement.