Troubled Alt-A mortgage lender Impac Mortgage Holdings Inc. said Friday morning that it would delay filing its fourth quarter results as it negotiates settlement of outstanding repurchase liabilities and looks to refinance its remaining warehouse borrowings. In a filing with the Securities and Exchange Commission, the company said it expects “additional disclosures in the 2007 financial statements” to result from its efforts, although it didn’t provide further details. Impac has been the subject of speculation that it may not survive the crunch pushing many independent mortgage lenders out of business, having posted a net loss of $1.3 billion during the third quarter. The loss pushed the company’s net worth into negative territory, it said at the time. The Irvine, Calif.-based lender also said that two key executives will depart at the end of this month, including Chief Investment Officer Andrew McCormick and Chief Operating Officer Richard Johnson. Neither positions will be filled upon the executives’ departures, with Impac citing “changes to the company’s business plan.” Impac CEO Joseph Tomkinson has been in the news recently for his involvement in a lawsuit between two REO auction companies, in which he was allegedly duped by investors looking to steal the business secrets of an auction firm his company had backed. For more information, visit http://www.impaccompanies.com.