Contract C340 involves the realignment of 420m of the Docklands Light Railway between Custom House and Victoria Dock Stations to release the site for portal construction.
The 355m long and 12m wide tunnel portal will be built in two phases to allow for the launch and recovery of tunnel boring machines during 2014.
Vinci beat rival bidders Costain/Skanska, which recently completed the Royal Oak Portal, as well as Bam/Kier, Balfour Beatty and Morgan Sindall.
Five new tunnel portals will be constructed as part of Crossrail at Royal Oak, Pudding Mill Lane, Victoria Dock, North Woolwich and Plumstead.
Andy Mitchell, Crossrail Programme Director said: “Crossrail has now awarded the last remaining tunnel portal contract. Construction of Royal Oak Portal was completed ahead of schedule last year.
“Main construction of the portals at Pudding Mill Lane and Plumstead are now underway. Construction of the North Woolwich portal will begin in May 2012 with Victoria Dock portal commencing in autumn 2012.”