French motorway and airport operator Vinci and Lineas, a company linked to Portuguese group Mota-Engil, had decided to exercise their pre-emption rights and buy out Atlantia, the Italian group said in a statement.
Atlantia, which decided in June to sell its motorway unit Autostrade per l'Italia, is reshaping its asset portfolio.
The Italian group said Vinci and Mota-Engil would buy the stake in Lusoponte pro-rata and would pay 55.7 million euros ($65.59 million) in total.
A previous contract signed to sell the operator of the Vasco da Gama bridge and the 25 de Abril bridge to MM Capital Partners will be scrapped.
($1 = 0.8493 euros)
(Reporting by Francesca Landini; editing by Barbara Lewis)