AIA Group Ltd <1299.HK>, Asia's No.3 insurer, is exploring an offer for Dutch bancassurer ING's roughly $6 billion (3 billion pound) Asian insurance operations, sources said, as the planned sale of the business, expected to attract heavy interest from rivals, kicks off.

AIA, which is about 33 percent owned by American International Group Inc , has invited four banks to make pitches to win advisory roles for a potential offer, two sources familiar with the process told Reuters.

The sources declined to be identified as they were not authorised to speak to the media. An AIA spokeswoman declined comment.

(Reporting by Denny Thomas; Editing by Jonathan Hopfner)