BEIJING, March 6 -- A new wave of anti-corruption inspections have kicked off as the Communist Party of China (CPC) graft-busters marched into 26 state-owned companies.

The companies, mostly energy and telecom giants, include China National Nuclear Corp., China National Petroleum Corp., China Electronics Technology Group Corp., China National Machinery Industry Corp., China Huaneng Group, State Grid, China Mobile and China Telecom. Many are among the world's top 500 companies.

Inspectors from the CPC's Central Commission for Discipline Inspection (CCDI) will be based at the companies for about two months. They will check the firms' operational procedures and handle complaints and petitions, especially those concerning the implementation of Party discipline, the central authorities' frugality campaign and the promotion of officials, the CCDI said at a briefing on Friday.

The commission has finished five rounds of inspections since the 18th CPC National Congress in late 2012, exposing corruption at a number of state-owned enterprises and government departments.

In the latest inspection results publicized last month, the inspection authorities said that China Unicom officials had colluded with contractors or suppliers and abused their power to seek money or sex. The Shenhua Group was also described to have manipulated power in coal trade to gain "black gold".