The delay came as the conglomerate sued its chip business partner Western Digital for interfering in the sale, one day after the US firm resubmitted a bid for the unit. The lawsuit pushes the war between the two partners to new heights and further complicates prospects for a deal.
Toshiba had wanted to have a signed agreement for the sale of the unit by Wednesday, the day of its annual shareholders meeting.
The hotly contested auction has seen a consortium, led by Japanese government investors and including US private equity firm Bain Capital, chosen as preferred bidder but the group's offer was only hastily and awkwardly put together this month.
That bid has been largely orchestrated by Japan's trade ministry, which is keen to keep semiconductor technology under domestic control.
Chief Executive Satoshi Tsunakawa said the firm was now aiming for an agreement with the preferred bidder consortium as early as possible and a completed transaction by the end of the financial year in March.
"It is taking time to smooth out differences in opinion among members of the consortium", he said, after apologising for a string of humiliating setbacks that include Toshiba's demotion to the second section of the Tokyo bourse.
Western Digital, which jointly runs Toshiba's main semiconductor plant, claims that its partner is breaching joint venture contracts and is seeking a US court injunction to prevent any deal that does not have its consent - actions that prompted Toshiba's lawsuit on Wednesday.
Tsunakawa lambasted Western Digital at the shareholders meeting, saying it had been interfering in the sale. But the head of Toshiba's chip unit also said the Japanese company was prepared to make concessions and hoped to resolve the dispute as soon as possible. Toshiba argues that Western Digital's bid for the memory unit presents antitrust questions and is too low in price.
Western Digital has said it offer meets the $18 billion minimum demanded by Toshiba - a figure that appears to match the amount offered by the preferred bidder.
Western Digital has also said it is strongly opposed to SK Hynix's participation and has threatened further legal action. Toshiba's lawsuit, filed with the Tokyo District Court, seeks around $1 billion in damages.
The Japanese firm also said it had shut out Western Digital employees based outside their Yokkaichi chip plant from accessing information relating to the two companies' joint venture - a move that threatens to impede R&D work on next-generation NAND memory chips. Western Digital declined to comment on the lawsuit. It said in a statement it had reiterated its concerns about the sale process and SK Hynix's participation to Toshiba.
The U.S. court hearing for its injunction request is scheduled for July 14.
