Assuming your AA and BA flights are on one ticket, AA's rules will apply since AA is the overwater carrier.
As for your Malev flights, it looks like it's a separate ticket. If so, Malev's rules will apply for those flights.
Refer to this thread on IATA rule 302
http://www.flyertalk.com/forum/bmi-diamond-club/1200793-new-iata-interline-baggage-rules.html
Last edited by seawolf; Jul 15, 2011 at 9:00 pm