BEIJING (REUTERS) - The state parent of China Southern Airlines Co Ltd, one of the targets of Beijing's anti-graft campaign, has closed overseas bank accounts, taken action against corrupt executives and stopped free rounds of golf for premier clients.

The government has been pushing for improved public disclosure by state firms as it steps up a nationwide campaign for greater transparency to fight corruption.

China Southern, which was inspected by the Central Commission for Discipline Inspection (CCDI) late last year, has taken disciplinary action against 25 executives since then, cut down the number of its agents and increased the ratio of direct sales.

It has also cut down the number of its overall bank accounts to 567 from 689 and mandated all its subsidiaries to have one banking account only, according to a statement posted on the website of CCDI.

China Southern had also started to monitor 55 of its 133 overseas banking accounts on a regular bases and aimed to cover the remainder before the end of the year, it added.

The carrier had also stopped entertaining its premier clients with free rounds of golf and its own executives were no longer allowed to accept expensive gifts.

The commission's anti-graft efforts at state firms coincide with the imminent roll-out of ambitious new guidelines to overhaul China's inefficient state sector.

The party has targeted 26 major state-owned firms for inspections this year, including China National Petroleum Corporation, Sinopec Group, China National Offshore Oil Corp, Shenhua Group, China National Nuclear Corp, China Southern Power Grid and China Power Investment Corp.

Separately, the Commerce Ministry said that Wang Shenyang, head of its cooperation department, was being investigated for infringing rules against extravagance by "participating in golf and other events organised by companies".