Ethiopia releases protest leaders
Three minibuses have reportedly left the prison while the group's supporters whistled and shouted for joy outside.
The group always said the trial was political and refused to enter a plea, leading to the men's conviction.
Ethiopia came under strong international pressure over the trial, and some donors cut aid.
But Ethiopian Prime Minister Meles Zenawi denied that he was following US orders to free the 30 Coalition for Unity and Democracy leaders and six others convicted over the protests.
"The Ethiopian government isn't willing and is unable to be run like a banana republic from Capitol Hill. Some individuals appear to be entertaining such illusions," he said.
He also said that some of the international pressure had been "shameful".
Among the 30 are CUD leader Hailu Shawel, the mayor-elect of the Addis Ababa Berhanu Nega and several other MPs and councillors from the capital.
Five others were convicted in absentia.
Mr Meles also said their rights to vote and contest elections would be restored.
But he said the MPs had boycotted parliament for two years and so may be unable to reclaim their seats now.
The head of the European Union 2005 election observers in Ethiopia had condemned the life sentences as "farcical" and "inhumane".
After the state prosecutor called for the death penalty, the US urged the government to "promote reconciliation" in the final sentence.
The government always said it could not interfere in the case until the legal process had finished.
Some 193 people died after thousands of people protested against the election results.
Most of those were protesters, killed by the security forces.
Tens of thousands of people were arrested.
"We believe that the sorry saga of the orange revolution is fully behind us," Mr Meles said.
The government denied charges of ballot-rigging and points out that it introduced multi-party elections to Ethiopia.