The results were hit hard by a write-down of the value of goodwill, or intangible value, for some insurance assets in the United States.
Third-quarter net profit was 371 million euros ($512 million) after "divestments and special items" totalling 671 million euros, the company said in a statement.
"While the option of one IPO remains open, we are going to prepare ourselves for a base case of two IPOs for our insurance businesses," ING announced.
One would be a "Europe-led IPO with solid cash flow combined with strong growth positions in developing markets, and one separate US-focused IPO with a leading franchise in retirement services".
"The aim is to create a strong and profitable US Insurance business that can be IPOed when earnings and market circumstances improve," said ING chief executive officer Jan Hommen.
ING hopes to conclude the separation of its banking and insurance operations by the end of 2010.
An IPO involves the owner of assets, a company or the state, offering part or all of them for sale for the first time as independently quoted shares on a stock exchange.
IPOs are closely watched, partly as an indicator of general sentiment on the market and as a possible opportunity to invest in a new entity at the start of its listed life.
ING reported that its net result had slumped by 499 million euros in the third quarter of 2009 and 1,09 billion euros in the second quarter of this year.
"Net results in the third quarter of this year included special items and divestments totalling 671 million euros, of which the 513 million euros goodwill write-down related to Insurance US was the primary component".
ING said it expected the separation of its banking and insurance branches would trigger a charge in the fourth quarter, reflected as a write-down of about one billion euros before tax.
The company's results were lower than a net profit of 953 million euros predicted by analysts polled by Dow Jones Newswires.
Total underlying income for the group, which employs 105,000 people around the world, was 12.8 billion euros in the quarter compared to 11.8 billion euros a year earlier, the statement said.
The underlying result before tax was 1,53 billion euros, up 91 per cent from a year earlier, carried by banking activities which recorded an underlying result before tax of 1.51 billion euros compared to 18 million euros for insurance.