Pakistan cited reports of Omar's death as the reason for the delay in negotiations, amid fears they could trigger a potentially bloody succession battle and further deepen divisions within the militant movement.
Mullah Akhtar Mohammad Mansour was appointed leader at a meeting of the Taliban's top representatives, many of whom are based in the Pakistani city of Quetta, according to the sources who were present at the shura, or gathering.
"The shura held outside Quetta unanimously elected Mullah Mansour as the new emir of the Taliban," said one commander at the Wednesday night meeting.
"The shura will release a statement shortly," he said.
Siraj Haqqani, leader of the powerful Haqqani militant faction, will be a deputy to Mansour, both commanders added.
Mansour will be only the second leader the Taliban have had, because Omar, an elusive figure rarely seen in public, founded the ultra-conservative Islamist movement in the 1990s.
The Taliban eventually conquered most of Afghanistan, imposing strict Islamic law before being driven from power in 2001 by a U.S.-led military intervention.
"There has always been Mullah Omar. So this is a completely new situation," said Bette Dam, author of an upcoming biography of the Taliban leader.

Latest News from World News Desk