SYDNEY, Sept 11 — Australian law firm Slater & Gordon Ltd today said it was preparing to sue major banks and wealth managers for charging excessive fees and paying below-market rates on cash holdings on retirement savings accounts.

Slater and Gordon said the planned class actions were triggered by a powerful inquiry into the conduct of the country's financial industry, which has heard that firms in the A$2.6 trillion (RM7.6 trillion) superannuation, or pension, sector, had not acted in the best interests of investors.

Initial findings from the Royal Commission strongly criticised pension funds run by National Australia Bank , Commonwealth Bank, Australia and New Zealand Banking Group and No. 1 wealth manager AMP Ltd for regulatory breaches including overcharging customers and failing to act in their best interest.

"We will launch a series of class actions against the big bank-owned super funds that we think may be liable for this conduct," the law firm said on a website it set up to publicise the lawsuit and invite participation.

It said one example was a superannuation fund parking its cash holdings with a parent bank which then paid interest below rates available from other institutions.

"The interest from the parent bank is so low that some investors in the cash option are receiving returns as low as 1.25 per cent a year — which is even below the RBA (Reserve Bank of Australia) cash rate," the website said.

The firm said it would target Commonwealth Bank and AMP first.

Spokespeople from Commonwealth Bank, AMP and NAB did not immediately respond to requests for comment. A spokesman from ANZ declined to comment. — Reuters