The tower sold for $2.8 billion, or about $1,474 per square foot. The deal broke the record for the highest price ever paid for a single office building, previously held by Kushner Companies' $1.8 billion purchase last year of 666 Fifth Avenue. Macklowe Properties sold the GM Building to help pay off overdue short-term debt on the seven Midtown office buildings Macklowe bought in a highly leveraged deal last year. Macklowe purchased the trophy tower for $1.4 billion in 2003. Boston Properties acquired a 60 percent stake in the GM Building, paying around $890 million in cash and assuming the $1.9 billion in debt, due to mature in 2017. The Boston Properties-led group also paid around $1.1 billion for three other Macklowe office properties in Manhattan (see below).