Costello, however, won't budge on his initial stance. "I can tell you unequivocally, that's nonsense," he responds. "Finding space and moving 1,000 jobs from New York to Sioux City, Iowa is a whole different animal. There's labor, technology, all kinds of analyses that other firms don't do and cannot do."

Jones Lang LaSalle managing director Ken Siegel says his firm is also able to compete on the site selection playing field. "We have that capacity in house," he tells GlobeSt.com. "Four or five years ago we hired a number of employees from one of Wadley-Donovan's competitors and are now offering site selection as part of our platform of services."

Siegel say that if a client comes in "with their firm of choice, we'll do the real estate piece and work with the firm that they brought to the table. If they don't have a firm then we'll do the work because we have that capacity."

"Everybody says that they can do everything," Costello counters. "We're taking a different approach by saying that we can't do everything, but what we can do, we do better than anyone else. We now have the ability to serve our corporate client base with true site selection. We are positioned in the industry to take a lead role in assessing our clients in location decisions that have a pervasive place in their overall operations."

But according to Siegel, "We have people in house with the same experience as Dennis Donovan. What we do is exactly parallel to the Wadley-Donovan practice. We just happen to call it part of Jones Lang LaSalle.

A spokesman for Insignia/ESG also disputes G&E's primacy in the site selection stakes and says Insignia, like its competitors, has long been offering such options to its clients. "I don't know how they can make that claim," he tells GlobeSt.com. "You can't be in real estate and not be able to provide site selection."