No. Only Singapore Airlines really offers this, and you will not find the info documented anywhere on their website, so you must confirm it with them in advance as essentially it's a goodwill gesture. The best way to do this would probably be to put a booking on hold and have them update the baggage allowance to 40kg before ticketing. Otherwise, get something in writing.
Other airlines offer 'migrant fares' which when you do the maths often just seem to be the standard cost plus the cost of an extra bag!
I think some have had success with this: http://www.iomaustralia.org/projects_selfpayers.htm# ...but shop around.