The National Trust, Civic Voice and The Heritage Alliance are to take over the co-ordination of the annual Heritage Open Days programme from 1 October.
English Heritage will continue to fund the initiative until March 2015, while the partnership aims to ensure its future in order to continue opening up sites of historic interest.
Loyd Grossman, chair of The Heritage Alliance, said: "English Heritage proved a good friend to the sector when it rescued the event in 2009, and we're grateful for its continued support in making sure the transition is smooth."
