Not to mention EI, IB and AY are in oneworld. IIRC, BA codeshares with AY U.K.-HEL.

At least on U.K.-Australia, there is some competion in the form of SQ and less-well-placed others. Anyways, BA is essentially codesharing with QF as it's dropped all service to Australia except Sydney and let QF take the pax from/to SIN.