PITTSBURGH — A federal judge has denied an effort by retail pharmacy groups to prevent pharmacy benefit managers Express Scripts Inc. and Medco Health Solutions Inc. from merging.

Published reports said Judge Cathy Bissoon of the U.S. District Court for the Western District of Pennsylvania on Wednesday rejected a request by the pharmacy trade organizations for a preliminary injunction to halt the merger of the two PBMs.

The Federal Trade Commission approved the $29 billion Express Scripts-Medco merger deal on April 2, and the same day the two companies announced the completion of the deal.

On March 29, the National Association of Chain Drug Stores, the National Community Pharmacists Association and nine pharmacy operators filed a lawsuit to block the merger, claiming the deal violates antitrust law. Though the FTC ended up clearing the merger deal just days later, the plaintiffs had sought a court order for the PBMs to keep their assets separate until their claims were addressed.

"NACDS and NCPA and the nine community pharmacy plaintiffs believe we presented a compelling argument for the court to issue a ‘hold separate’ order to suspend the combination of Express Scripts and Medco until the merits of our complaint could be considered in full," NACDS and NCPA said in a joint statement released Wednesday. "It is important to note that the judge has not yet ruled on the merits of the case or the motion to dismiss, so the case is continuing."

Bissoon heard arguments in the suit on April 10 but didn’t issue a ruling on the case.

On Wednesday Bissoon said she will rule on a request by Express Scripts to dismiss the pharmacy groups’ lawsuit before issuing a decision on a permanent injunction against the merger of the PBM companies, according to reports.

Last week, the Consumer Federation of America, National Consumers League, National Legislative Association on Prescription Drug Prices and U.S. PIRG submitted an amicus curiae brief in the U.S. District Court in Pittsburgh to support the suit by NACDS, NCPA and the pharmacy operators, which are based in or have a presence in Pennsylvania.