A new lawsuit filed in Manhattan federal court targeted the private equity owners of a so-called “blank check” company, claiming that firm, a type of popular mechanism for conducting corporate mergers, had left investors holding the bag on a bad merger.

The class action complaint, filed Wednesday in the U.S. District Court for the Southern District of New York, took aim at Churchill Capital Corp. III, a special purpose acquisition vehicle, or SPAC, that merged with health care cost specialist MultiPlan Corp. in October.