Sept 14 (Reuters) - Australia's federal court has fined pension funds run by National Australia Bank A$57.5 million ($41.9 million) for charging fees with no service to thousands of retirees, the country's corporate watchdog said on Monday.

The court ruling says NULIS Nominees and MLC Nominees, trustees of pension fund products sold by NAB, deducted about A$100 million in fees from about 677,000 retirees between 2012 and 2018 for plans in which they either did not have an adviser or did not need one.

The decision comes after a civil lawsuit was by Australian Securities and Investments Commission (ASIC) in September 2018 following a public inquiry that exposed widespread misconduct in the financial sector. (https://bit.ly/3iue6qm)

NAB admitted in a separate statement that its trustees' conduct was "misleading" and breached certain ASIC acts. It also said that by May 2019, a total of A$117 million had been paid to members who were affected.

Last month, the company agreed to sell the MLC business to IOOF Holdings Ltd for A$1.4 billion, while Australia's financial regulator imposed additional conditions to the licenses of NAB's pension funds to improve financial controls. ($1 = 1.3734 Australian dollars) (Reporting by Anushka Trivedi in Bengaluru. Editing by Gerry Doyle)