The transition comes just six days after European leaders chose Van Rompuy for the new EU job (EurActiv 20/11/09), a remarkably short period for politically complex Belgium and despite fears that Leterme's second term in office could be as unstable as his first.
After a succession of talks among party chiefs, the king charged another former premier, Jean-Luc Dehaene, with proposing ways to resolve conflict in the linguistically divided country.
The move does not resolve the disputes between Dutch-speaking Flemish parties and their French-speaking counterparts, but gives Leterme a better chance of success at his second attempt.
Leterme was the clear winner of the 2007 federal election, but struggled for nine months to form a government, which then lurched for another nine months from one crisis to another.
He resigned last December over alleged political meddling in the break-up of Belgo-Dutch financial services group Fortis. He has since been absolved.
By contrast, Van Rompuy's 11 months in charge have seen no sign of the internal tensions that had prompted media speculation that the country might break apart. During the height of the government crisis in 2007, central bank governor Guy Quaden warned that it risked increasing Belgium's budget deficit.
Economists say Belgium can ill afford renewed government paralysis at a time of economic crisis. Indeed, the fragile recovery is likely to remain the government's main issue.
However, Leterme will need to find a consensus on redrawing the political boundaries around Brussels and on further powers that can be devolved to the regions, which already have a wealth of control over areas such as agriculture and foreign trade.
Dehaene is to put forward possible solutions to the boundary problem, one of the most divisive issues in Belgian politics and one the constitutional court says the country must resolve before the next federal election due in 2011.
The government will hope to resolve these matters before July, when Belgium takes over the six-month EU presidency, an organisational role held by each member state in turn.
On a positive note, Leterme will inherit a government that has already resolved the budget for 2010 and 2011 and a cabinet far less divided than when he departed last December.
(EurActiv with Reuters)
