Libya could have a new special envoy by the end of this Friday, according to a letter seen by Reuters news agency.
UN Secretary-General António Guterres plans to appoint a former Senegalese minister to lead efforts towards peace in Libya.
If the 15-member UN Security Council approves the appointment by consensus, Abdoulaye Bathily could take up the position immediately.
Pending the Council's approval, Bathily would replace Jan Kubis who stepped down last December.
Libya has had little peace since the 2011 NATO-backed uprising that ousted long-time autocrat Muammar Gaddafi, splitting the nation in 2014 between rival eastern and western factions and dragging in regional powers. Libyan oil output, a prize for the warring groups, has repeatedly been shut off.
Libya's worst fighting for two years suddenly hit the capital, Tripoli, last Saturday.
The clashes erupted and ended suddenly.