May 7 (Bloomberg) -- Brian Cowen takes over as Ireland's prime minister today, aiming to reverse an economic slowdown and persuade Irish voters to approve a European Union treaty that would streamline the bloc's decision-making.

Chosen as leader-elect by the governing Fianna Fail party last month, Cowen will be confirmed by the parliament in Dublin to succeed Bertie Ahern, who was pressured to resign by a corruption probe after almost 11 years in power.

Finance minister since 2004, Cowen, 48, assumes office as rising unemployment and falling home prices end a decade-long boom and as his constituents weigh the fate of the EU treaty in a June 12 referendum. Ireland was alone among the EU's 27 countries in asking voters to ratify the treaty, which will die if rejected, forcing European policy makers back to the negotiating table for a third time after the failure of a comparable pact in 2005.

``It could be argued that Bertie got out at just the right time,'' said Diarmaid Ferriter, a historian and author of ``Transformation of Ireland: 1900-2000.'' ``Bertie was lucky, he inherited the boom in a sense. That's not the case with Cowen.''

Best known for brokering peace in Northern Ireland, Ahern endorsed Cowen as his successor after winning a third term last May. Ahern announced his resignation on April 2, saying his government's work was being ``overshadowed'' by the investigation. A tribunal is examining whether Ahern accepted money from businessman Owen O'Callaghan to assist with construction of a shopping mall in the early 1990s. Ahern has denied wrongdoing and both men have said no payments were made.

Investment Plan

Cowen has said he won't comment in detail on his policy plans until he's formally elected premier, a position known in Gaelic as the Taoiseach, at about 3:30 p.m. He said on April 9 that he will push on with a 184 billion-euro ($286 billion) plan to improve roads, telecommunication networks and housing.

``We should not repeat the errors of the past, which was to withdraw capital investment,'' Cowen said. ``We need to continue to put in the building blocks for future growth in our economy by not reneging on the commitments we made to ourselves.''

Support of the EU treaty in Ireland fell to 35 percent from 43 percent in February, according to a survey commissioned by the Sunday Business Post and published on April 27. The margin of error was 3 points.

Cowen's ascent may help his ruling coalition win the vote, as party supporters take the opportunity to publicly back their new leader.

Avoiding Defeat

``Cowen's party won't want their new leader to start his tenure with a defeat at the polls,'' said Kevin Rafter, the author of five books on Irish politics. ``Especially with the international profile the ballot will receive.''

The vote will take place as economic growth deteriorates.

Ireland's unemployment rate has risen to the highest level in almost nine years, with companies including Dell Inc., the world's second- biggest personal-computer maker, cutting jobs. Irish house prices fell 8.9 percent in March from the same month last year, while the benchmark stock-market index, the ISEQ, has dropped by a third during the past year.

The government's budget deficit widened in the first four months of the year to 3.7 billion euros, compared with a deficit of 638 million euros in the same period last year.

``After the boom years of the so-called Celtic Tiger, Irish people will find a new Taoiseach who has to say 'no' much more regularly than his predecessor,'' said Rafter. ``It is all change now for the Celtic Tiger.''

To contact the reporter on this story: Dara Doyle in Dublin at ddoyle1@bloomberg.net

Last Updated: May 6, 2008 22:26 EDT