Three London disability charities - the Royal Association for Disability Rights, the National Centre for Independent Living and Disability Alliance - plan to merge and form a new organisation that would provisionally be called the Disability Rights Partnership.
All three are all based in London and have a combined annual income of about £3m.
Liz Sayce, chief executive of the Royal Association for Disability Rights, also known as Radar, said the charities had 35 staff and there were no plans to make any of the posts redundant.
She said the proposal to merge the charities was based on increasing the campaigning power of the charities and was nothing to do with financial difficulties.
Sayce said she would not have further details about how the merged charity would be run until the consultation closed in November.
A statement issued on behalf of the three charities said they had been in talks about the merger for 18 months.
It said: "The announcement this week that Disability Alliance's chief executive is due to depart at the end of September offered an opportunity to inject new energy into the discussions about the potential for a unified organisation and accelerated the process of consultation with members of all three organisations."