However, a chairman for 2011 has yet to be appointed after Saxby took over the reins from BI Worldwide's head of events Mark Taylor during Summer Eventia at Glasgow's SECC.
Allen has now been appointed to the vice chairman role, but will not necessarily take up the position of chair from 2011.
Saxby said: "Traditionally Eventia has filled the chair position from the position of vice chair but in a departure from this Rob has taken the post on the basis that he will not necessarily take up the chair position. We have a number of board members who are potential candidates including those that have recently joined us and this move allows us more time to allow them to build up their board experience."
Allen added: "It felt like the most obvious thing to do - I am heavily involved as treasurer and, in filling the role in this way, I leave my options open and also allow one of a number of very able board members to fill the role in due course."
The news follows Motivcom's group executive director Nigel Cooper's resignation from the Eventia board in August, two months after he was reappointed.
Cooper is a past chairman of Eventia and stepped down from the association in 2007 to concentrate on Motivcom.
He was re-appointed as a board member during Eventia’s AGM in London on 10 June.