Japan Post Holdings plans to sell a stake in Japan Post Bank that could raise ¥630 billion ($4.2 billion), the latest disposal in the former state-run giant’s decade-long privatization efforts.

The company will sell as many as 416.1 million shares at a discount of 2% to 4% of the stock’s market price, according to a term sheet of the deal. Japan Post Bank plans to buy back as much as ¥60 billion of shares and cancel them.

The sale could bring the holding company’s stake in the banking unit to below the 50% threshold it had pledged to do by the end of fiscal year ending March. That would give more autonomy to the bank, which is currently largely banned from lending business and manages most of its assets in securities such as foreign and domestic bonds.