The private-equity firm Kohlberg Kravis Roberts & Co. is pursuing a minority investment in ING Group NV's U.S. online bank, according to a person with knowledge of the matter.

A potential deal may involve ING keeping a majority stake in the unit, known as ING Direct USA, or selling it to another bidder, the person said, speaking on condition of anonymity because the talks are private.

General Electric Co. and Capital One Financial Corp. submitted bids last week for the bank, people with knowledge of the sale talks said this week.

ING, of Amsterdam, is under European Union orders to sell the U.S. unit by 2013 as a condition of its government bailout. ING is also divesting its insurance units to comply with the terms.

Kristi Huller, a KKR spokeswoman, and Carolien van der Giessen, a spokeswoman for ING, declined to comment.