The chairmen of FTSE 100 engineering giant Babcock International (LSE: BAB.L - news ) , British Land (LSE: BLND.L - news ) and the AA have put their names to an open letter from Heathrow chairman Sir Nigel Rudd urging ministers to support expansion of the west London airport.
Utilize the input text as a context reference, choose the right relationship between 'Babcock International' and 'London' from the options.
Options: developer, location of formation, employer, publisher