The architects are the latest to be dropped as BAA whittles down its list of consultants. The client has already ditched four quantity surveyors and Bovis and Schal as construction managers.
It is reducing its lists of preferred consultants because an internal reorganisation has resulted in less reliance on external firms. Delays to Heathrow Terminal 5 have also reduced its expected workload.
Pascal & Watson and GMW are retained as BAA's architects, with HOK working on planning for Terminal 5, and Geoffrey Reid Associates working for BAA development arm Lynton.
Richard Rogers Partnership, which was not on the list of preferred architects, will continue to give BAA "strategic" advice.
Percy Thomas Partnership chief executive John Rudge said: "This is not untypical of what has happened with a lot of clients that have set up preferred lists and 'term' appointments.
"You put a lot of work into getting on the list and then get very little out of it at all. I'm neither delighted or disappointed to be left off, because after the initial enthusiasm BAA gave very little work out through this arrangement.
"BAA has just asked us to bid for something outside the term appointment, so it doesn't seem to matter if you are on the preferred list or not," he said.