NEW YORK CITY-Office rents in some of Manhattan's most valued areas are probably about to level off as prices in newly appealing markets are set to soar, according to new industry research.

In the latest Marks Paneth Gotham commercial real estate monitor—a survey of 100-plus owners, managers, brokers, agents, attorneys and accountants—a quarter of top New York City commercial property executives predict that rents in the Flatiron district, Grand Central and Northeast Midtown areas likely will stabilize

Meanwhile, survey respondents expect office space will probably skyrocket in selected emerging office locations, including the Garment Center/Herald Square, Downtown Brooklyn and Hell's Kitchen/Far West Side. That's what 16%, 13% and 12% of executives said, respectively.

"The subtext may be that businesses will gain a bit more leverage as they negotiate leases in the white-shoe parts of Midtown and the putatively red-hot Flatiron/Midtown South district," says William Jennings, partner-in-charge of the real estate group at Marks Paneth.

In terms of valuation, 38% of executives report that Manhattan commercial real estate is “moderately overvalued” compared to property in other major global cities. And yet, survey respondents don't see a significant risk when investing in Manhattan commercial property. Just 2% said there's a “high” risk associated with such investments. A total of 35% said there's a “moderately low” or “low risk,” and 48% said the risk is “moderate.”

Survey respondents also weighed in on which new developments will have a big impact on the market and which ones won't have an effect. Over a six-month period, the number of property executives who believe the Hudson Yards project will be the mega-development with the biggest positive long-term impact on surrounding commercial property values increased significantly, from 52% to 34%.

But many industry participants also are optimistic about the potential positive effects of the Second avenue subway—24% said it will have the biggest impact on surrounding values—while 20% are pegging their hopes on the LIRR East side access to Grand Central station.

Far fewer investors and industry watchers had high hopes for some of Downtown's upcoming development. Just 4% think the new World Trade Center will have the most positive long-term impact.