SK Hynix said its board had approved its participation in a consortium led by Bain Capital that plans to purchase Toshiba's memory chip unit for 2 trillion yen ($17.7 billion).
SK Hynix said in a statement it will invest 395 billion yen.
Toshiba's board agreed last week to sell the unit to the Bain group. However, the signing was delayed because consortium member Apple demanded new terms on chip supply in return for funding.
Toshiba aims for a signed deal as soon as possible.
The Bain-led consortium will hold 49.9 percent of the voting rights in the chip unit, while Toshiba will hold 40.2 percent and Japan's Hoya Corp will own 9.9 percent.
The Bain-led consortium also includes Dell, Seagate Technology Plc and Kingston Technology.