The family of businessman Sean Quinn and Irish Bank Resolution Corporation have agreed to mediation of their long-running and bitter dispute over liability for loans of €2.34bn.

The High Court was told by lawyers for the Quinns this morning that the sides had agreed to mediation.

Mr Justice Robert Haughton said he was pleased as this dispute lent itself to mediation and he wished the parties well.

Preparations for the hearing of the action by Patricia Quinn and her five adult children will continue in the meantime.

The action, initiated in May 2011 and due to open on 3 June, has been deferred to January 2016 pending the outcome of criminal proceedings against former Anglo chairman Sean FitzPatrick, due for hearing in October.

The Quinns' senior counsel, Martin Hayden, had told the court on 3 June, after the deferral was directed by the judge, the adjournment should be used for mediation.

IBRC had said finalisation of the case was in the public interest, counsel said.

Two other hearing dates for the Quinns' action were also previously deferred, also on the application of the DPP and on similar grounds of criminal proceedings against various former Anglo executives and officials.

The legal costs of the Quinn proceedings to date are estimated to run to several million euro.

Separately, lawyers for IBRC have served a motion for judgment on Sean Quinn Senior, seeking indemnity from him against any sums awarded to his family should they win their case or, without prejudice to the indemnity claim, damages for alleged misrepresentation, breach of warranty of authority, fraud, negligence and conspiracy.

Mr Justice Haughton was told today lawyers for IBRC had clarified in correspondence the motion, to be dealt with at the end of the family's action should the latter proceed, relates only to assets in the bankruptcy estate of Mr Quinn. Any judgment is also contingent on the family winning their case.

Larry Brennan, solicitor for Mr Quinn, said, given the clarification the motion related only to the bankruptcy estate and not any assets acquired by Mr Quinn since he exited from bankruptcy, Mr Quinn had no position on the motion.

This was because of a previous ruling in 2012 by Mr Justice Peter Kelly that Mr Quinn, then a bankrupt, had no entitlement to defend the motion.

Mr Gallagher said IBRC's position was the motion for judgment always related to assets in the bankruptcy estate and there was no confusion.

IBRC previously joined Mr Quinn as a third party to the family's case.

After the Official Assignee in bankruptcy declined in 2012 to defend the bank's claim against Mr Quinn who, as a bankrupt at that point, could not personally defend it, the Commercial Court ruled the bank could seek judgment in default against Mr Quinn at the trial of the family's action.

In their case against IBRC and its special liquidator Kieran Wallace, the Quinns allege €2.34bn loans made by Anglo to various Quinn companies were for the unlawful purpose of propping up the bank's share price.

Following a Supreme Court decision last March, they cannot pursue aspects of their claim alleging the loans are unenforceable.

The defendants previously joined Sean Quinn Senior and two former senior Quinn Group executives, Dara O'Reilly and Liam McCaffrey, as third parties.

The third parties have denied the bank's claims they acted as agents of the Quinn plaintiffs concerning disputed share pledges and guarantees.