The U.S. Justice Department has sued to block tech giant HPE from acquiring Juniper Networks, the networking firm, citing antitrust concerns.

WASHINGTON—The Justice Department on Thursday sued to block the tie-up of Hewlett Packard Enterprise and Juniper Networks, a $14 billion deal that would join the second-largest and third-largest providers of wireless networking solutions for large corporate customers.

The US Justice Department sued to block Hewlett Packard Enterprise Co.’s $14 billion acquisition of Juniper Networks Inc., arguing the tie-up would harm competition in the market for enterprise wireless equipment used by large companies,