* Retail, office properties hit hard; apartments recover

* Washington DC is top market; San Francisco, Boston next

By Nick Zieminski

NEW YORK, Nov 5 (Reuters) - The U.S. commercial real estate market, slammed by the credit squeeze and recession, is likely to hit bottom in 2010, according to a survey of industry investors, developers, lenders and consultants.

Commercial real estate values will fall 40 percent, on average, from their peaks in mid-2007, and up to 50 percent in some sectors, according to the 2010 edition of Emerging Trends in Real Estate, released on Thursday by the Urban Land Institute and PricewaterhouseCoopers LLP.

It will be the worst commercial real estate decline since the Great Depression, eclipsing the 1990s savings-and-loan crisis, according to the report.

"Not surprisingly, the overwhelming sentiment (of) interviewees remains decidedly negative, colored by impending doom and distress over prospects for an extended period of anemic demand and costly deleveraging," the report said.

Hardest-hit will be retail and office properties, reflecting a weak job market and cautious consumers. A growing population of men and women in their 20s will help the apartment sector recover earlier than other commercial real estate sectors, the report said.

"It's going to be a year that's going to provide investors with tremendous opportunities at generational, cyclical lows," said Susan Smith, a director in the real estate advisory practice at PricewaterhouseCoopers in New York. "There's a tremendous amount of money waiting on the sidelines."