Kyrgyzstan's ex-security chief Felix Kulov has reportedly agreed not to stand as president in July elections.
Felix Kulov was imprisoned for four years under Askar Akavev
Mr Kulov was one of the main leaders of the opposition which drove President Askar Akayev out of office in March.
He and acting President Kurmanbek Bakiev had been seen as a key contenders to replace the ousted leader in the summer elections.
But sources in Bishkek say Mr Kulov is now willing to serve as prime minister if Mr Bakiev becomes president.
"He will go in tandem with Bakiev... like a prime minister with stronger powers and the right to form the government," a source close to Mr Kulov told Reuters news agency.
The agreement will considerably strengthen Mr Bakiev's chances of becoming president.
It should also ease fears that the election might cause further unrest in this poverty-stricken central Asian nation.
Mr Kulov is more popular in the north, where he is originally from, while Mr Bakiev's supporters live mostly in the volatile south.
Mr Kulov was imprisoned for corruption and abuse of power under Mr Akayev's rule - charges he says were politically motivated.
He was released from jail in the early hours of Mr Akayev's overthrow on 24 March, and took charge of security soon after his release.
The Supreme Court overturned the convictions against him on 11 April, legally clearing his way to stand for the presidency.