TOKYO (Reuters) – Toshiba Corp (6502.T) told its main banks on Monday it has not signed the $18 billion sale of its semiconductor business because Apple Inc (AAPL.O), a member of the buyer group, has not agreed on key terms, two people involved in the deal said.

The struggling Japanese conglomerate announced on Wednesday that it had chosen a consortium led by U.S. private-equity firm Bain Capital LP to buy the prized chip unit, a move that would end a nine-month sale process and plug a huge hole in Toshiba’s finances, preventing it from being removed from trading on the Tokyo Stock Exchange.

But the signing of the deal, initially expected to be the next day, has dragged on, forcing Toshiba to explain the predicament to its bankers on Monday and, the sources told Reuters, ask the lenders to roll over 680 billion yen ($6.1 billion) in credit lines set to expire on Sept 30.

The lenders have been demanding that Toshiba sign a definitive agreement as a condition for the funding.

Details of the issues with Apple couldn’t immediately be ascertained.

Toshiba said in a statement to Reuters, “While we cannot comment on the detail of the deal procedure, we aim to sign the agreement with the purchaser as early as possible.”

Apple didn’t immediately reply to an emailed request for comment.

Press representatives for Sumitomo Mitsui Banking Corp and Mizuho Bank, the biggest of Toshiba’s seven main lenders, couldn’t immediately be reached outside office hours.