TORONTO — Dundee International REIT (TSX:DI.UN) is buying a 1.5-million-square-foot portfolio of office properties in Germany for $568-million.Dundee says the acquisition is being financed through some $354-million in new mortgage debt and cash on hand as well as some of the proceeds of a major equity offering.Under the offering, Dundee is selling, on a bought deal basis, 20.2 million units of the REIT at $10.90 per unit for gross proceeds of $220-million.