Anthem is countering Bloomfield, Connecticut-based Cigna a day after its smaller rival sued to terminate a $48 billion buyout agreement.
Indianapolis-based Anthem on Wednesday sought a restraining order to block that maneuver and force it to comply with the deal, which has already been blocked by a federal judge.
The rapid-fire consolidation in the health care industry appears to be hitting a wall. On Tuesday, Aetna said it was abandoning its $34 billion acquisition of Humana. That was followed by the Cigna lawsuit. Both deals drew in the Justice Department and separate federal courts ruled the deals could hurt consumers.
Cigna Corp. is seeking a $1.85 billion termination fee from Anthem and more than $13 billion in damages.
Anthem Inc. said Wednesday that Cigna doesn't have a right to terminate the agreement.