Cisco Systems Inc., the largest maker of networking equipment, ended a partnership with ZTE Corp. amid concerns over the Chinese company’s sale of equipment to Iran.

“Cisco has no current relationship with ZTE,” John Earnhardt, spokesman for San Jose, California-based Cisco, wrote in an e-mailed statement Monday.

ZTE, along with Huawei Technologies Co., provides opportunities for Chinese intelligence services to tamper with U.S. telecommunications networks for spying, according to a U.S. congressional report released Monday. ZTE sold to an Iranian telecommunications company a surveillance system capable of monitoring landline, mobile and Internet communications, Reuters reported in March.

Margrete Ma, a spokeswoman for ZTE, didn’t immediately respond to requests for comment left outside regular business hours. Cisco’s severed ties to ZTE were reported earlier by Reuters.