Disagreement over whether to keep Toshiba's existing management following a potential buyout caused friction between two of its suitors and is now stoking concern among banks, sources have said, further complicating an already uncertain process.

Japan Industrial Partners (JIP), the private equity firm since selected by Toshiba as a preferred bidder, originally teamed up with state-backed fund Japan Investment Corp. (JIC) in a first round of bidding earlier this year.

But the two parted ways for the second round. Differences over JIP's plan to retain Toshiba CEO Taro Shimada and his team were a source of friction between the two bidders, according to two sources familiar with the talks.