01:53 PM EDT, 07/09/2024 (MT Newswires) -- A UnitedHealth Group ( UNH ) shareholder filed a lawsuit Monday against the company's directors for allegedly failing to establish an antitrust firewall between units after the acquisition of Change Healthcare and for making misleading statements, breaching their fiduciary duties.

Portia McCollum, in a derivative lawsuit filed in the US District Court for the District of Minnesota, alleged the company officers made "materially false and misleading statements" from March 14, 2022, to Feb. 27, 2024.

UnitedHealth ( UNH ) had said it would establish a firewall between its Optum unit and Change Healthcare to address antitrust concerns raised by the Department of Justice, according to the lawsuit.

"Despite assurances to the contrary, there was never a meaningful technological separation," the lawsuit said.

The company's stock price began to fall in February after the Wall Street Journal reported that the DOJ reopened an antitrust investigation into UnitedHealth ( UNH ), the lawsuit said.

The lawsuit is seeking damages and certain reforms at the company to improve corporate governance.

UnitedHealth ( UNH ) didn't immediately respond to a request for comment from MT Newswires.

UnitedHealth Group ( UNH ) shares rose 1% in recent Tuesday trading.

Price: 494.07, Change: +4.73, Percent Change: +0.97