The company, which had previously tabled a bid for AssetCo earlier this year, is understood to have returned with a 4p-per-share offer.
AssetCo’s directors had previously rejected a 21p-per-share bid from the investment firm in March.
However, the company has been close to the brink for several months, forcing chief executive Tudor Davies to consider a cut-price sale.
The company has debts of about £80m, which it has struggled to refinance, and was almost wound up earlier this year for an unpaid tax bill.
Belfast-based lender Northern Bank, which is owed £1.3m by Assetco, had launched a creditors’ petition to wind up the company, due to be heard in court last week.
The case has been put back until 11 July, after AssetCo applied for an administration order.