Update at 1045GMT 07APR14
QATAR Airways and British Airways starting Tuesday (08APR14) begins reciprocal codeshare operations. This codeshare operation covers service beyond London Heathrow and Doha, excluding flights between the 2 airports.
QATAR Airways operated by British Airways QR5900 – 5999 series
London Heathrow – Amsterdam
London Heathrow – Belfast City
London Heathrow – Dublin
London Heathrow – Glasgow
London Heathrow – Hamburg
London Heathrow – Leeds/Bradford
London Heathrow – Newcastle
British Airways operated by QATAR Airways BA6100 – 6199 series
Doha – Addis Ababa
Doha – Dhaka
Doha – Dar es Salaam
Doha – Entebbe
Doha – Islamabad
Doha – Karachi
Doha – Lahore
Doha – Peshawar
