The Philippines said Wednesday it would end Chinese technical involvement in running the country's power grid, partly due to national security concerns.

All 16 Chinese technicians currently working for the National Grid Corporation of the Philippines will be sent home by July, Energy Secretary Jericho Petilla told AFP.

The State Grid Corporation of China has a 40-percent stake in the Philippine firm, which operates and maintains the nation's power grid, but Petilla said the government wanted only Filipinos to run it.

Asked if security issues were behind the decision to send the Chinese home, Petilla said via text message that "it certainly is a concern of NSA," referring to the government's National Security Advisor.

He said the Department of Energy also believed that Filipinos now had the skills to do the work being done by the Chinese, which complicates their visa status.

"Hence, to harmonise those concerns, it was agreed last year that the management and technical operation will be run by an all-Filipino team by July," Petilla said.

However, Petilla said the Chinese company would retain its stake in the National Grid Corp. This means that two Chinese will remain as board members representing their company.

Political relations between the Philippines and China have steadily worsened in recent years over their rival claims to parts of the South China Sea, which is believed to contain vast gas and oil deposits.

The Philippines has charged China with fortifying islets in the disputed area to possibly turn them into armed outposts, while accusing it of bullying diplomatic tactics.

It has also infuriated Beijing by asking a United Nations tribunal to rule the Chinese maritime claims are invalid. China has refused to recognise the legal proceedings.

Over the weekend, prominent Philippine politician Senator Miriam Santiago expressed concern over foreign involvement in the National Grid Corp.

Without specifically naming the Chinese company, Santiago said the electric power industry had been "infected by a national security virus".