CVS Pharmacy Inc. and Rite Aid Corp. accused AstraZeneca Pharmaceuticals on Tuesday of conspiring with three generic drugmakers to delay competition for its blockbuster antipsychotic Seroquel XR.

The antitrust lawsuit, filed in U.S. District Court for the Southern District of New York, targeted patent-infringement settlements AstraZeneca had reached with Handa Pharmaceuticals and Accord Healthcare Inc., which had separately sought regulatory approval to bring generic versions of Seroquel to market.