TOKYO, April 14 (Reuters) - Apple Inc is considering investing at least several billion dollars in the chip business put up for sale by Toshiba Corp, public broadcaster NHK reported, citing an unidentified source.

Apple wants to take a stake of more than 20 percent in Toshiba's chip business, while convincing Toshiba to maintain a partial stake to keep the business under U.S. and Japanese control to allay the Japanese government's concerns, the report said.

Appls is considering a plan in which Taiwan's Foxconn would also own a stake of around 30 percent in its bid, it added.

Toshiba is now in the process of selling its memory chip unit to raise cash to cover writedowns at U.S. nuclear unit Westinghouse that have plunged it into crisis.

(Reporting by Junko Fujita, Tim Kelly and Chang-Ran Kim; Editing by Edwina Gibbs)