Some 51 Advantage Travel Centre agents did not renew their membership to the association at the annual renewals.
The move follows the franchise deal with Airtours which led to 31 Scotway agents leaving to join the new Scottish agent’s consortium, SPARC.
Advantage president Roger Smith said the 11-strong Sibbald Travel agents had transferred to Thomson, two to First Choice and seven were non-franchise members.
There are currently 350 agents in the franchise scheme but Airtours is keen to expand this to 500 by the end of the year.
Colin Heal, chairman of rival consortium ARTAC Worldchoice, claimed a significant proportion of the ex-Advantage members had applied to join ARTAC.