* Competition regulator considering new banking inquiry
* Inquiry to look at barriers to entry in retail banking-SMH
* ACCC concerned over lack of formal support for inquiry-SMH
* Australian treasurer says he's not focused on new inquiries
SYDNEY, Oct 4 (Reuters) - Australia's competition regulator said on Friday it is considering an investigation into the banking sector, less than a year after a public inquiry exposed widespread wrongdoing and led to billions of dollars in costs for the industry.
The Sydney Morning Herald reported the Australian Competition and Consumer Commission (ACCC) was planning a fresh inquiry into barriers to entry in retail banking, a sector dominated by the country's "Big Four" banks.
The regulator confirmed that an inquiry was under consideration and said it was considering which stakeholders to engage with, but declined to give details.
"We are currently discussing potential options for our next inquiry, including the various approaches we might take," an ACCC spokeswoman said.
Australia's four largest banks - Commonwealth Bank of Australia CBA.AX , Westpac Banking Corp WBC.AX , ANZ Banking Group ANZ.AX and National Australia Bank NAB.AX - dominate about 80 percent of the retail banking sector.
They are facing increased regulatory scrutiny after the sector-wide Royal Commission inquiry last year found they had pursued profit ahead of customers' interests. A separate inquiry by the Productivity Commission also found the sector lacked competition.
The four banks have booked expenses of over A$8 billion ($5.4 billion) to refund customers for overcharged fees, miss-sold products and non-compliant financial advice in the wake of the Royal Commission, with NAB this week doubling its compensation pot. Josh Frydenberg said he would give a new inquiry his consideration but added: "Right now I'm not focused on new inquiries". focused on implementing the recommendations of the most comprehensive inquiry, namely the Royal Commission that we have just had," he told reporters.
Citing internal ACCC documents, The Sydney Morning Herald reported the regulator planned to meet executives of HSBC Holdings PLC HSBA.L and Macquarie Group Ltd MQG.AX , both of which are trying to expand their retail banking businesses in Australia.
The documents showed some members of the ACCC's Financial Services Board were concerned about a lack of government support for a new inquiry, and opposition from the banks.
Prime Minister Scott Morrison said earlier this week he was disappointed in the major banks for denying borrowers the full benefit of the latest central bank monetary easing. = 1.4815 Australian dollars)