The decision came on Oct. 15 at the close of a coalition council meeting in the Parliament building in Tallinn.
The Pro Patria Union earlier in the day confirmed it would join the opposition at Tartu City Council after failing to reach an agreement with the Reform Party, which is in the majority there.
The new commission will comprise two members from each parliamentary faction in the coalition, said coalition council chairman Andres Tarand in a news conference after the council meeting.
The coalition agreement signed by Pro Patria, the Moderates and the Reform Party in 1999 would not require any revisions, he added.
Tiit Sinisaar, head of Pro Patria's parliamentary faction said it was high time for change, given that the opposition is ahead in opinion polls.
The commission would enhance mutual communication and help ensure the parties stuck to the same message, said Tarand. "If some of our partners outside the coalition state something that can hurt the coalition's interests, we should be able to make it clear that it is not the official point of view," Tarand said.
Prime Minister Mart Laar of the Pro Patria party said the coalition's failure to work properly had been demonstrated in the process leading to the election of the country's new president, Arnold Ruutel, who is a member of the opposition People's Union.
On Oct. 15 Laar said the coalition parties should act in accordance with the coalition agreement and stick together at least until the next parliamentary elections.
Siim Kallas, minister of finance and chairman of the Reform Party, agreed. "If the coalition wants to last until the next elections, we have to be sensible," said Kallas. "We have agreed to stay away from collective rows."
Marju Lauristin, chairwoman of the Moderate party's parliamentary faction, agreed that internal communication within the coalition had been poor, though not as poor as portrayed in the media.
The two most important issues the coalition parties cannot agree about are administrative reform and electronic identity cards. The Reform Party has put forward a bill to make the cards voluntary, while the rest of the coalition support obligatory electronic identity cards.
Pro Patria's withdrawal from the ruling coalition in Tartu came after it failed to reach agreement with the Center Party of Edgar Savisaar, which is in opposition at national level.
Pro Patria had failed to come to terms with its usual partner the Reform Party as a result of disputes over the presidential election process.
Peeter Tulviste, a disappointed Pro Patria presidential candidate and chairman of the City Council, told the Baltic News Service on Oct. 15 that joining the opposition was "not a tragedy."
Tartu Mayor Andrus Ansip meanwhile said an agreement between his party - the Reform Party - and the Center Party would be signed this week. According to a draft copy of the accord between the Centrists and the Reformists, the post of City Council chairman currently held by Tulviste will go to Aadu Must of the Center Party, a professor of history at Tartu University. The Reformists will offer the two deputy mayors' posts to the Center Party.
But the Pro Patria Union might not give up its posts voluntarily and may instead wait for a no-confidence motion, said Tulviste.