Dr Thomson, formerly chief executive of Newham LBC, joined the Audit Commission just over a year ago and is being lined up as the next controller.
Steve Bundred at Camden LBC and Barry Quirk at Lewisham LBC are the only serving chief executives to make the list.
Interim GLA chief executive Bob Chilton will be interviewed, as will Local Government Association head of social affairs John Ransford, formerly the chief executive of North Yorkshire CC, and Transport for London chief executive Anthony Mayer.
panel will include an independent adviser, Tony Travers, the Greater London Group director at the London School of Economics.
The rest of the panel will be drawn from members of the appointments committee, plus all four political group leaders. There will be a single round of interviews in the third or fourth week of September, with an appointment expected in late September or early October.
But appointments committee chair Len Duvall stressed that the size and composition of the panel and the length and nature of the interviews have yet to be finalised.
The appointments committee is made up of the following assembly members:
Len Duvall (chair), Brian Coleman(deputy chair), Lynne Featherstone, Samantha Heath, Elizabeth Howlett, Darren Johnson, Eric Ollerenshaw, Trevor Phillips,
Graham Tope and Jeannette Arnold.