We have been on this route several times, all with BA in economy, changing planes at LHR. We are thinking of trying a different airline, as BA has gone downhill big time, but would want to change planes in Europe. Going to Malpensa is not an option, and we cannot afford anything other than economy as we don't fly often enough to accrue any miles or perks.

Air France flies to LIN from Paris, KLM from Amsterdam, Lufthansa from Frankfurt, Iberia from Madrid, and Alitalia from Rome (all reachable nonstop from LAX.) Pick 'em.

matrix.itasoftware.com

This is the most comprehensive search for airline routes that I know. It is run by Google, its operation is fairly clunky, and it does not sell tickets, But I think it contains more info than Google's own travel service.