Beijing has called on Manila to make efforts to safeguard Chinese companies in the Philippines, Chinese Foreign Ministry spokesman Hong Lei said on Thursday.

"China has noticed related reports. We hope the Philippine authorities could deal with related issues in a fair manner," Hong said.

Philippine Energy Secretary Carlos Jericho Petilla was reported as saying on Monday that the Philippine government will not renew the work visas of 18 Chinese experts employed by the National Grid Corporation of the Philippines when they expire this year.

Petilla's remarks came after Senator Miriam Defensor Santiago warned that the Philippines has been infected by a “national security virus,” referring to the 40 percent stake of Chinese state firm State Grid Corporation of China in NGCP.

Hong said the Chinese company has made a significant contribution since 2007 when it won a 25-year concession to operate the country's power transmission network.

"We hope the Philippine side could handle related issues with fairness, safeguard the legitimate rights and interests of Chinese companies, and create a good environment for foreign investors," Hong said.