The UN Security Council is expected to organise first "straw poll" or informal vote on the candidates seeking the post of Secretary General in the second half of July, its president Jean-Marc De La Sabliere of France said.
The poll is meant to gauge the support that a respective candidates enjoy among the council members but a final decision might come only in late September or early October.
However, some members would like the selection process to be over by August end so that the new incumbent could have interaction with world leaders when they come to New York for the UN General Assembly's annual session.
Indian nominee UN Under-Secretary-General Shashi Tharoor, Sri Lanka's Jayantha Dhanapala and Thai Deputy Prime Minister Surakiart Sathirathai are currently the main candidates. But more could be nominated in the intervening period.
There is no time limit for a member state nominating its own candidate and names can be introduced till the end of the process.