The ruling Democratic Party of Japan is seeking to amend laws to require external audits for privately owned asset management firms in a bid to avoid a recurrence of the AIJ Investment Advisors Co. case.

The DPJ has launched a working team under its financial committee to discuss changes to rules governing investment managers for pension money, Tsutomu Okubo, a lawmaker who leads the panel, said in a recent interview. Okubo, 50, expects a bill to amend the Financial Instruments and Exchange Law will win Cabinet approval as early as this month and then be sent to the Diet.

Japan's financial regulator is investigating asset managers following the Feb. 24 suspension of AIJ, which has failed to account for the more than ¥210 billion ($2.6 billion) it oversaw for clients, including pension funds. The case has raised concern over the safety of retirement assets at a time when more than a fifth of the nation's population is over 65.