OPES Prime clients have voted to wind up the failed stockbroker as liquidators enter the delicate last stages of closed-door talks aimed at squeezing hundreds of millions of dollars from its former financiers, ANZ and Merrill Lynch.

Opes' liquidators, John Lindholm and Adrian Brown, of Ferrier Hodgson, believe ANZ theoretically should pay creditors between $135 million and $200 million to reverse unfair and uncommercial transactions struck in the days just before the broker collapsed.

They also want receivers appointed by ANZ to hand over a $70 million surplus generated by Merrill Lynch when it sold shares Opes clients had vested with the broker.

But during six hours of meetings yesterday with creditors of Opes and a related company, Leveraged Capital, the liquidators repeatedly emphasised that, although they remained confident they could strike a settlement with the banks, the process was tortuous and uncertain.

Creditors' final payout, if any, also remains far from clear.

The vote to liquidate Opes Prime crystallises the creditors' claims from the close of business tonight.

Many creditors wanted the wind-up postponed until the results of mediation were clear. But they were outnumbered by $26.8 million of proxies held by litigation funders IMF, $11.94 million in the hands of law firm Slater & Gordon, about $39 million held by Singapore-based Anthony Soh of Asia Pacific Links, and $17.8 million of proxies voted by Mr Lindholm.

ANZ's lawyer, Brendan Watkins, of Minter Ellison, abstained from exercising the bank's right to vote; its claim is worth about $145 million.

Mr Lindholm said although mediation talks were due to end on October 20, "I am not going to take a die-in-the-ditch stand on the date — because I know the outcome is not pretty for creditors".

His legal adviser, Tony Troiani, of Mallesons Stephen Jaques, told creditors the liquidators' argument was that Opes should not have entered any financial deals after March 19 and 20 when it was clearly insolvent: "The company should have gone into administration then."

Mr Troiani said the banks were "well aware" that the liquidators could convene courtroom examinations where ANZ and Merrill Lynch executives would be compelled to explain their actions before the collapse.

"We are going to face off again on Friday and on Monday, and all through the weekend if we have to," Mr Troiani said. "No stone is going to be left unturned to avoid the Armageddon scenario, which is three to five years of litigation."

Already the banks are threatened with two potential class actions, initiated by Slater & Gordon and IMF, plus a raft of legal claims by individual clients.

In the background is a huge investigation by the Australian Securities and Investments Commission, which is examining insolvent trading, the actions of Opes directors in the weeks before it failed, curious share transactions stretching back to early December, and the company's failure to call clients who were deeply indebted on margin-loan accounts.

ASIC is also examining what the Australian Securities Exchange did to regulate Opes Prime before it collapsed and how it handled the aftermath.

Mr Lindholm said ASIC's team was "looking at everything".

"They have been very diligent," Mr Lindholm said. "They have been doing section 19 examinations (compulsory formal interviews) on as many people as I have ever seen."

Back in April, Mr Lindholm suggested creditors might ultimately get up to 30¢ in the dollar, assuming they recovered sums from Opes directors — Laurie Emini, Julian Smith and Anthony Blumberg — and several big clients who did not meet margin calls.

Yesterday Mr Lindholm could not provide any estimate of likely distributions.

He said volatile share trading had dramatically altered creditors' claims; instead of claiming money, some former clients now owed Opes millions of dollars.

Opes clients were owed about $585 million at March 27 but, as share prices slumped, the sum dropped to $400 million at September 22. It is now closer to $300 million.