BNP Paribas has bought the Belgian government's stake in BNP Paribas Fortis which it has held since a bailout saved Fortis from collapse in 2008.
The 25% stake has been priced at €3.25bn (£2.73bn, $4.37bn) and will see a €900m capital gain for the Belgian government, bringing hope for UK officials that they too can sell off their holdings in RBS and Lloyds at a profit.
In a joint statement, Belgium's Prime Minister Elio Di Rupo and Minister of Finance Koen Geens said: "The objectives set by the government when the Belgian state initially invested were fully achieved. The bank has met its commitments despite a challenging environment. The moment had therefore come for the Belgian State to disengage from BNP Paribas Fortis."
Jean-Laurent Bonnafé, chief executive of BNP Paribas, said: "The partnership with the Belgian state brought the stability that was needed for the integration to occur in the best conditions for the employees and the clients of the bank and we are grateful to the Belgian state, which also remains one of our major shareholders, for this collaboration."
He added: "We will continue to develop BNP Paribas Fortis in accordance with the principles that have been ours during the integration phase, both in labor matters and in terms of support to the economy."
The news from Fortis will bring hope for the UK government which is looking to sell its stakes in RBS and Lloyds after bailing out the two institutions during the crisis.
In September the UK government sold off a 6% slice of its stake in Lloyds, leaving it with 32.7% left invested in the business. It has not yet successfully reprivatised any of its 81% holding in RBS, which has undergone a transformation of its balance sheet and has created an "internal bad bank" for its toxic assets.