Oxford Properties, the real estate arm of the Ontario Municipal Employees Retirement System, is proposing to build a huge $3.5-billion development in downtown just north of Rogers Centre. Oxford proposes a 4.3-million-square-foot, mixed-use complex on a four-acre site to be called Union Park. Stories Wednesday recall that it is Oxford Properties that is building the nearly completed Hudson Yards project in Manhattan. Union Park plans call for two office towers, 58 and 48 storeys, about 800 rental apartments across two buildings, and 200,000 square feet for retail. Three acres will be devoted to public space, including an urban park over the Union Station rail corridor, which spans Blue Jays Way to the John Street Bridge. Urban Toronto Also Toronto Sun