While director Christopher Nolan is yet to officially sign on for a sequel to The Dark Knight, there's no doubt that one will be made.

Now, Batman-on-Film.com is quoting sources that claim the next Batman movie is slated to begin pre-production around February 2009 in Chicago for a summer 2009 shoot.

"What's interesting is that info seems to be originating from folks who worked on The Dark Knight behind the scenes -- set builders, stuntmen, film crew, etc. -- in Chicago," the site says.

"As far as this buzz coming from former The Dark Knight crew members, there's probably something to this as you can't hire these guys at the very last minute. If sets need to be built and other miscellaneous pre-preproduction projects need to get done, I suspect that readying these things a year and a half/two years in advance is NOT out of the question."

We'll certainly have more on this story as news breaks.