The Disasters Emergency Committee is seeking an agreement with all major British broadcasters after both the BBC and Sky refused to broadcast the umbrella group's Gaza Crisis Appeal.
In its annual report, published today, the coalition says it has held discussions with broadcasters to "clarify the decision-making process for appeals".
Brendan Gormley, chief executive of the DEC, which is a coalition of 13 humanitarian aid charities including Oxfam, the British Red Cross and Save the Children, told Third Sector he hoped to sign a memorandum of understanding with major broadcasters later this summer.
Gormley said he hoped the memorandum would be a collective commitment on how decisions over whether to allocate airtime to new campaigns would be made.
The annual report shows that the British public has given more than £24m over the past year for the agency's three major appeals for the Gaza, Congo and Myanmar crises.
It also says that a small number of the DEC's 13 member agencies have been given until 2011 to meet revised membership criteria or face being expelled from the group.
In order to qualify as a DEC member, organisations must show they bring in at least £4m of private giving and distribute a minimum of £10m of overseas humanitarian aid each year.
Gormley declined to reveal which organisations were falling short of the criteria, but said: "The trustees have said that just because you are in the club doesn't mean you are in it forever."
The DEC also plans to create a donor database to bring together information on people who give to different appeals, because information on people who have donated to individual appeals has previously been kept separate.
The committee is assessing a shortlist of data-management companies to tender a contract for the database, which should be operational by the autumn.