The London Stock Exchange (LSE) will now disclose to a number of stockbroking firms the identities of parties who purchased shares from them through MMI Stockbrokers.

The main firms involved are understood to be K&H Options, Merrill Lynch and Credit Suisse and these firms will now themselves pursue "unsettled" debts of approximately £13 million due from the MMI clients.

The development reduces the assets of the liquidated company and significantly lessens the work of the liquidator, Mr Tom Kavanagh. Mr Michael Collins SC, for the LSE, told the High Court that under its rules concerning default situations, the exchange must inform counter-parties to contracts executed through agents such as MMI of the identity of the other parties to those contracts. The exchange then had no further role, he said.

The liquidator had already provided the identities but Mr Collins wanted an order of the court so there would be no question concerning the propriety of the LSE having the information.

It was disclosed during the hearing that, in a letter to the Revenue, the liquidator believed that putting the counter-parties in direct contact with the principals could make it "difficult" for MMI to collect commission from the sales it negotiated.

The court also heard that the Irish Stock Exchange did not have a default rule similar to that of the LSE, but that it did have rules that may amount to the same thing. This issue is to be considered by the court on Friday.

It is understood the bulk of the £13 million in unsettled deals relates to London dealings. Most of the debts have been outstanding for a number of months. Shares in Dana Petroleum and Tullow Oil are understood to be involved in a significant percentage of the debt.

Mr Bill Shipsey SC, for the liquidator, indicated there might be an issue concerning the price of Liberty Asset Management - mentioned in court as MMI's assets were outlined - on which there was a contract of sale prior to the liquidation.