The transaction would exceed 2.5 billion euros ($2.60 billion), the newspaper said.
Abertis is a toll road operator controlled by Italy's Atlantia and Spanish engineering firm ACS.
An Abertis spokesman was not immediately available for comment. OMERS and CPP Investment Board did not respond to requests for comment.
($1 = 0.9600 euros)
(Reporting by Christina Thykjaer, editing by Inti Landauro and Jason Neely)