The new leader of the Conservatives should be in place by 9 September, a week later than initially mooted.
The 1922 executive committee of Tory MPs, which will oversee the contest, had suggested David Cameron's successor should be announced on 2 September.
But the party's board has recommended an extra week to allow for the "full participation" of members.
Under the proposed timetable, nominations would open from Wednesday and close at noon on Thursday.
The Conservative Party's board's recommendation needs to be approved by the board of the full 1922 Committee on Wednesday. If approved, nominations would open straight after the Wednesday meeting.
In a statement, the board said: "The board and the 1922 committee both agree that the leadership election should take place as speedily as practical considerations allow.
"In order to ensure there is full participation by the membership, the Party Board recommends that the date of the declaration of the leader is the 9 September 2016."
David Cameron has said he intends to stand down as prime minister and Conservative leader, after the UK voted by 52% to 48% to leave the EU. He had campaigned hard for a Remain victory and said "fresh leadership" would be needed to lead Brexit negotiations in future.
MP John Baron is said to be considering running - and Boris Johnson, Theresa May and Stephen Crabb are likely to throw their names into the ring.
Other potential candidates include Nicky Morgan, Jeremy Hunt, Andrea Leadsom and Liam Fox. Chancellor George Osborne and Justice Secretary Michael Gove have ruled themselves out.
The BBC's political correspondent Carole Walker said Graham Brady, the chair of the 1922 committee, has met the party's chief whip to discuss complaints that party whips had already been getting involved in the leadership campaigns.
The Conservative leadership election rules
The party's 1922 committee will oversee the contest. Its executive has suggested the contest should follow the system used to elect David Cameron in 2005, which would see MPs pick two candidates to put to the wider membership.
MPs wanting to stand need to be nominated by two others to get onto the ballot paper. If there are three or more candidates, a ballot or series of ballots will be held of all the party's 331 MPs to whittle down the field to two. In each round, the candidate with the fewest votes will be eliminated.
After that, a vote of the wider party - in which all Conservative members will have a say - will be held to choose the winner, with hustings taking place.
The suggested timetable is for a leader to be in place by 9 September, with nominations opening on Wednesday 29 June and closing by noon on Thursday 30 June. However, this will have to be approved by the Conservative Party's board and the 1922 committee as a whole.
If agreed, it means the party will have a new leader in time for its autumn conference, which starts on 2 October - the deadline David Cameron had set when he announced his intention to resign.