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

Juniper Networks stock fell Thursday after the Justice Department moved to block a planned acquisition of the networking company by Hewlett Packard Enterprise.The Justice Department filed a complaint in California district court that seeks to block the merger on antitrust grounds.

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.