CANNES, March 14 — Germany is midway through a four-year real estate crisis that will lead to more losses and distressed sales of unwanted properties, the head of Commerzbank’s real estate business told Reuters.

The euro zone’s largest economy is in the grip of its worst property slump since at least the 2007-9 global financial crisis, after a sharp rise in borrowing costs and a higher proportion of riskier lending tipped the sector into one of Europe’s biggest downturns.