National Australia Bank may revisit its mid-2008 offer to Citigroup to buy the latter's Smith Barney retail broking franchise, The Age reported.Ownership of Smith Barney worldwide will change assuming Citi and Morgan Stanley finalise terms for a joint venture in retail broking in which Morgan Stanley would hold a 51 per cent stake.Morgan Stanley has no retail broking operation in Australia while Smith Barney has about 30 local advisers, according to The Age.