This is according to the Massachusetts Institute of Technology's Center for Real Estate.

Office buildings declined 5.5 percent last quarter, bringing prices to levels last seen in early 2007 as the real estate boom ended, according to an index produced by the Cambridge-based university, known as MIT.

The decline in the MIT index means prices for properties such as shopping malls, apartment complexes, office buildings and warehouses are more than 9 percent below peak values reached in mid-2007, the school said.

"This represents a continuation of the correction in commercial property market prices that began last fall - a correction triggered by the credit crunch caused by the subprime housing mortgage crisis and fueled by concerns about a recession,'' said Professor David Geltner, research director of the MIT/CRE, in a statement.

Commercial property values are holding up better than housing, Geltner said. Rental income, occupancy rates and mortgage delinquency rates remain low, he said.

The MIT index tracks prices that institutions such as pension funds pay or receive when buying and selling properties. It's based on prices of properties sold each quarter from the database that underlies the National Council of Real Estate Investment Fiduciaries Property Index and also makes use of the appraisal information for all of the currently 6,000 NCREIF properties. MIT developed the index in 2006.