Corporate dealmakers could be on the far side of the M&A moon. They exist in larger and larger numbers, and they exert considerable influence on corporate strategy and M&A, but to a world enamored of investment bankers, corporate lawyers and swashbuckling CEOs, they often do their work in the shadows. It certainly doesn't help that these in-house dealmakers often carry a wide range of disparate, and confusing, titles: corporate or business development officers, chief financial officers, general counsels, vice presidents of acquisitions and divestitures. And it doesn't help that their jobs vary so much depending on the company.

Larger corporations that regularly engage in dealmaking -- acquisitions, spinoffs, divestitures, joint ventures -- tend to build internal deal teams with permanent staffs that play a major role in vetting, executing and managing M&A deals, and, most importantly, in integrating the units after the close. Other corporations, which engage less regularly in M&A, tend to have smaller deal teams, often handing the job to a CFO or GC, or pulling together ad hoc teams when the occasion demands. Then there are those special cases, notably in companies dominated by powerful CEOs who control M&A, such as Warren Buffett at Berkshire Hathaway Inc. Buffett famously vets and negotiates many of Berkshire's deals personally -- though even there, someone (not Buffett) has to run the integration process.

For all of that complexity, corporate dealmaking over the last decade or so has emerged as a legitimate corporate discipline and career path, not to say something of a counterbalance to Wall Street. Despite the mix of titles and tasks, there has been a steady growth in the self-­consciousness of corporate dealmaking as a necessary and professional managerial competency, as important as finance or strategic planning, both of which it's deeply intertwined with.

But who are these often powerful, if obscure gatekeepers? A number of years ago, we began to track corporate dealmakers who could be identified with specific M&A transactions. This wasn't always easy, but we have been slowly generating names, particularly at major dealmaking companies, such as IBM Corp., General Electric Co. and Cisco Systems Inc. Our annual Most Admired Corporate Dealmaker awards have focused on in-house dealmaking talent from companies the transactional community deemed best of breed. Now we believe we have enough critical mass to move to the next step: the first-ever Corporate Dealmaker 100, a listing of heads of corporate dealmaking at the top 100 companies by market capitalization (see page 30).

Now some caveats. We have 100 companies -- getting those names was easy, thanks to help from Capital IQ, which provided the market cap ranking­ -- ­but in some cases we're still missing individual corporate dealmaker names; you'll see the NAs. Why? Some of the companies simply lack anyone that resembles a true corporate dealmaker. In others, such a function exists and the company either wants to keep it under wraps -- some chief executives demand the glory, which is why in our list we give their names as well -- or spokespersons simply don't know who they are or what they do.

We also stripped out the banks from this list. Some of the banks use their own internal investment banking resources if they need to do a deal (see sidebar, page 32), then pull teams together to execute the integration, from wrestling with IT problems to transitioning new employees to new benefits packages.

This listing is thus a work in progress, despite a sizable investment in reporting resources. Over the next few years, we hope to build out this list and expand the available information on this group; we'd appreciate all the help we can get from readers. Meanwhile, we think this list will begin to raise the curtain on a vitally important and rapidly evolving constituency for dealmaking services, whatever title you slap on them and whichever side of the moon they hail from.