Residential Capital LLC won court approval of a mediator for talks with creditors opposing the bankrupt mortgage company's $750 million settlement with parent Ally Financial Inc., Bloomberg News reported yesterday. Bankruptcy Judge Martin Glenn agreed to appoint fellow judge James Peck to try to resolve a fight over how much Ally should be forced to pay to avoid a lawsuit over what the company did before it put ResCap into bankruptcy and other issues. Unsecured noteholders represented by Wilmington Trust NA say that Ally is offering too little to resolve claims that it stripped ResCap of valuable assets. A bankruptcy examiner is investigating the settlement offer and plans to deliver a report in April.