* Settlement may expose bank to potential class action suits
* Westpac, NAB also accused of rate-rigging
* Court hearings adjourned till Wednesday
* NAB says it continues to be in discussions with ASIC
* Westpac notes that case facts different for each lender (Adds comments from Westpac, NAB and Moody's)
SYDNEY, Oct 23 (Reuters) - Australia and New Zealand Banking Group Ltd has reached a last-minute agreement to settle a case brought by the country's securities regulator accusing it of manipulating the bank bill swap rate.
Australia's third-largest lender, which had previously said it would defend itself against the allegations, did not give a reason for its decision to settle or disclose financial terms. It said it would make a more detailed statement in two days time after more progress had been made on the agreement.
The deal could open ANZ to possible class action lawsuits from shareholders and also throws the spotlight on Westpac Banking Corporation and National Australia Bank which are facing similar allegations that they rigged a benchmark rate used to price financial products.
"Any settlement was likely premised on them admitting that they've done the wrong thing, which does open the way up for class actions," said CLSA banking analyst Brian Johnson, although he added that the settlement sum with ASIC was likely to be immaterial in size.
ANZ said the financial impact would be reflected in the bank's annual earnings due on Thursday.
The court hearings had been due to start on Monday but have now been adjourned until Wednesday at the request of the Australian Securities and Investments Commission (ASIC).
Westpac spokesman David Lording, in an emailed statement, declined to say whether the bank was also likely to settle, but added: "ASICs case against each of the banks and the underpinning facts are all different."
NAB spokesman Mark Alexander said the bank continued to be in discussions with the regulator but declined further comment. Both banks have previously said they would dispute the claims in court.
ASIC's allegations that the three lenders were involved in rigging the bank bill swap reference rate (BBSW) is only one of several scandals engulfing Australia's banking sector in which lenders have also been accused of widespread abuses at their financial advice and insurance units.
Commonwealth Bank of Australia, the nation's No. 1 lender, is not part of ASIC's lawsuit.
But it has been taken to court by anti-money-laundering agency AUSTRAC which has accused it of more 50,000 breaches of anti-money laundering rules. ASIC has also launched its own investigation into the matter.
CBA has not disputed that it processed tens of thousands of illicit transfers but argues the breaches were largely caused by a software glitch and contests its level of responsibility.
The BBSW is the primary interest rate benchmark used in Australian markets to price home loans, credit cards and other financial products. ASIC, which filed the lawsuits last year, has alleged that rate-rigging at the lenders took place between 2010 and 2012. The method used to calculate the BBSW was changed in 2013.
Australia's four major lenders control 80 percent of the country's lending market and have posted record profits for years.
Moody's Investors Service on Monday improved its outlook on the banking system to 'stable' from 'negative', noting Australia's favorable economic trends, the banks' strong capital positions and stable profitability.
ANZ shares ended down 0.2 percent, in line with the broader market.
(Additional reporting by Byron Kaye in Sydney and by Shashwat Pradhan in Bengaluru; Editing by Stephen Coates and Edwina Gibbs)