Valad Property Group, an Australian real-estate investment trust that carried out more than $2bn of acquisitions in 2007, fell to the lowest in almost two weeks in Sydney trading after its co-founder resigned.

Valad shares tumbled 9% to 7c on the nation’s stock exchange. The company lost almost A$1bn ($747m) in market worth since June 30, dropping to A$112.6m today, after reporting an annual net loss because of property writedowns.

Stephen Day, who co-founded Valad in 1995, resigned as a director and is no longer employed by the group,