Japan's Toshiba Corp said it had yet to receive clearance from all regulators for the sale of its prized $18 billion memory-chip business by its self-imposed end-March deadline, but added it aimed to sell it as early as possible.

The conglomerate agreed last year to sell the world's second-biggest producer of NAND flash memory chips to a consortium led by U.S. private equity firm Bain Capital to plug a financial hole left by the bankruptcy of its U.S. nuclear unit.

It had faced a March 23 deadline to win approval from antimonopoly authorities to sell the business by March 31, but China has not yet given its approval. Toshiba no longer faces immediate insolvency or a delisting even if it does not meet the end-March deadline, as it raised funds from a share issue late last year.

Some activist shareholders oppose the sale saying that the $18 billion price tag undervalues the business and Toshiba should renegotiate with the Bain group or consider an initial public offering.