SL Green , the city’s largest office landlord, has agreed to sell 19 West 44th Street for $123.2 million to Deka Immobilien , a German real estate investor. That’s nearly double the $67 million that SL Green paid for the 292,000-square-foot building in 2004. The company plans to invest the $118 million in net proceeds towards 125 Park Avenue, which it agreed to buy from Shorenstein Properties …
