The US commercial property market is unlikely to recover before 2012 and office rents in New York and San Francisco may drop 20% through next year, a survey of property investors found.

Suburban office rents could fall as much as 20%, while downtown office rents may decline about 10 percent, according to the quarterly PricewaterhouseCoopers Korpacz Real Estate Investor Survey, released today.

'The biggest problem is that commercial real estate lags what happens in the economy,' Susan Smith, director of PricewaterhouseCoopers’ real estate advisory service, said in an interview. 'Companies are looking for ways to cut costs, many are continuing to reduce workers and are continuing to reduce their space needs.'