MILAN- Atlantia shareholder TCI welcomed a bid by Spain's ACS for the Italian group's motorway unit and said it expected Atlantia's board to "engage promptly ... to explore the offer".

"We expect the board of Atlantia to act in the best interest of all shareholders," TCI partner Jonathan Amouyal said in emailed comments to Reuters, adding the unit should be sold "to the highest bidder without any political interference".

(Reporting by Francesca Landini; writing by Valentina Za; editing by Agnieszka Flak) ((valentina.za@thomsonreuters.com; +39 02 6612 9526;))