Toshiba’s preferred bidder won’t secure letters of commitment from banks by year-end, casting yet more uncertainty over a deal as disagreements over lending terms persist after months of negotiations.

A consortium led by Japan Industrial Partners is in talks over bank financing totaling about ¥1.4 trillion ($10.6 billion) to take Toshiba private, but negotiations have stalled over covenants and collateral, preventing banks from deciding how much funding each would provide, people familiar with the matter said.

JIP has also requested additional subordinated loans and other forms of mezzanine capital, with talks still ongoing, the people said.