The Australian Federal Court has fined the country's second-biggest lender National Australia Bank a penalty of A$2.1 million ($1.35 million) for wrongfully charging customers periodic payment fees, the securities regulator said on Friday.

Between January 2017 and July 2018, National Australia Bank (NAB) continued to charge its customers periodic payment fees for transferring money despite knowing it had no contractual entitlement to do so, the Australian Securities & Investments Commission (ASIC) said.

The bank wrongfully charged 2,888 personal banking customers and 513 business banking customers payment fees on 74,593 occasions, totalling A$139,845, the regulator added.

NAB did not immediately respond to a Reuters request for comment.

"If systems have let customers down, we expect all financial institutions, especially our banks, to act quickly to reduce consumer harm," ASIC Deputy Chair Sarah Court said.

Over the recent years, Australian regulators have fined a slew of companies over breaches and non-compliance issues, with the "Big Four" banks penalised the heaviest after a Royal Commission into the sector exposed widespread misconduct.

($1 = 1.5588 Australian dollars)

(Reporting by Sameer Manekar in Bengaluru; Editing by Janane Venkatraman)