The Federal Reserve’s “Beige Book” — reporting on economic activity –  warns of one segment in which things probably will get worse instead of better.

What’s the likely economic black hole in 2010? Commercial real estate. Here’s why, according to the Fed:

An analysis of the economy shows a mostly up-and-down pattern for different segments, depending on what part of the country you look at. So, for instance, the housing market might be flat in one area but up in another.

Commercial real estate is the exception; it’s down just about everywhere.

The cause stems from a domino effect:

• Tight credit leads to shrinking businesses.
• Shrinking businesses lead to empty stores and offices.
• Empty stores and offices lead to a glut of available business sites.

To make matters worse, many regional lenders are stuck in commercial real estate ventures in troubled parts of the country — sort of a mini-subprime meltdown.

Click here for a detailed summary of the Beige Book findings.