The chairman of Proton has stepped down.

Asian media says the cause was former premier Mahathir Mohamad's continuing influence in the company.

Abu Hassan Kendut resigned early this week because he felt Mahathir, as an adviser to Proton with no formal executive position, was interfering with management efforts to revamp the automaker to face foreign competition as trade barriers come down in South East Asia, the Asian Wall Street Journal said.

Mahathir was appointed as adviser to Proton in April last year. He created the company in 1983 as part of Malaysia's drive into heavy industry.