Developer’s Big Manhattan Move Faces a Time and Credit Squeeze

Harry Macklowe, the New York developer, was flying high in February when he decided to buy a portfolio of prime Midtown Manhattan office towers for nearly $7 billion, using only $50 million of his own money. But as the crisis over subprime residential mortgages spills over into other real estate sectors, causing a severe tightening of credit, there is widespread talk in the industry that Mr. Macklowe is in deep trouble — so much so that he could lose control not only of the newly acquired portfolio but also of the G.M. Building and other properties that were used as collateral for short-term debt that must be repaid six months from now.