Sprint Nextel turned down bids from ZTE and Huawei Technologies because of US government concerns over possible dangers to national security from the Chinese vendors building critical infrastructure in the US, the Wall Street Journal reported on Friday.

Sprint, the nation's third largest mobile operator, rejected ZTE and Huawei's bids to modernise its network even though they were lower than those of three rival companies, the Journal reported. The other bidders were Ericsson of Sweden, Samsung Electronics of South Korea and Alcatel-Lucent, which is based in Paris and incorporates the former US telecom vendor Lucent.

Some US lawmakers have expressed concern over letting Huawei or ZTE participate in major infrastructure projects in the US because of concerns over possible links between those companies and the Chinese government and military. They have worried that the Chinese military could use equipment from the companies to disrupt US communications. The Journal reported that US Secretary of Commerce Gary Locke had called Sprint CEO Dan Hesse this week to voice concerns about possible deals between Sprint and the two companies, though not to ask him to reject the companies' bids.

Sprint, Huawei and ZTE could not immediately be reached for comment.