A breakaway faction of Zimbabwe's main opposition party, the Movement for Democratic Change (MDC), has chosen an ex-student leader as its president.
Morgan Tsvangirai led the MDC since it was formed six years ago
Arthur Mutambara was elected unopposed at a meeting of 3,000 of the faction's supporters in the city of Bulawayo.
Mr Mutambara led student protests against state corruption in the 1980s. He returned to Zimbabwe recently after being abroad for 15 years.
The MDC split has weakened opposition to President Mugabe, observers say.
The MDC, led since it was formed in 1999 by Morgan Tsvangirai, divided into two hostile camps last year when differences emerged over whether to contest senate elections.
The breakaway faction, known as the pro-Senate group, has accused Mr Tsvangirai of arrogance and failing to accept his party's decisions.
In front of several thousand delegates, Mr Mutambara promised to take the opposition forward in its efforts to oust Robert Mugabe, who turned 82 this week.
Mr Mutambara returned to Zimbabwe saying the MDC needed new leaders after several years of in-fighting over political strategy.
He is a member of the majority Shona ethnic group - seen by many analysts as essential for any party leader.
Most of the pro-Senate group are ethnic Ndebeles.
Mr Tsvangirai's MDC faction will hold its own party leadership congress in mid-March.