DOJ cited reduced competition in the wireless market as the biggest problem with the proposed $14 billion sale of Juniper Networks to Hewlett Packard Enterprise. The vendors say they plan to “vigorously defend the transaction in court.

The U.S. Justice Department has filed suit to block Hewlett Packard Enterprise Co.’s proposed acquisition of Juniper Networks Inc. for $14 billion. Officials submitted the complaint today to the U.S. District Court for the Northern District of California.

The Justice Department on Thursday sued to block the tie-up, a $14 billion deal that would join the second- and third-largest companies providing wireless networking solutions for large corporate customers.