Yahoo is closer to naming a new international head, according to sources, the last big slot left in the top management structure of CEO Carol Bartz.

While BoomTown is endeavoring to get the name of this international man of mystery, several sources said the company has come close to settling on a London-based media exec, who will move to and operate out of its Sunnyvale, Calif., HQ in Silicon Valley.

But it is unclear if or when a final appointment will be made.

That exec could be a lot of people, since Yahoo’s headhunter for the job–Heidrick & Struggles–has pretty much talked to the gamut of international Web muckety-mucks since the search started six months ago.

The many chatted up include: Former Bebo head Joanna Shields (nope, she has a noncompete from AOL); former Joost CEO Mike Volpi (nope, he just landed as a VC at Index Ventures), Microsoft (MSFT) consumer and online man in Britain Ashley Highfield (hmm, would he move so quickly after jumping from Project Kangaroo and the BBC?) and Gavin Patterson, head of the BT Retail unit.

But Yahoo could also opt for a more traditional media exec, said some sources.

In a memo to Yahoo staff after her reorganization in February, Bartz said that “international growth is critical for Yahoo!, which has become too reliant on its U.S. business over the years.”

Still, that key job remains unfilled, in an arena Yahoo has dropped the ball in recently, even as more nimble competitors like Google (GOOG) and Facebook thrive.

In the Yahoo (YHOO) management chart posted below, Bartz has filled the CFO role with Tim Morse and the customer advocacy slot with Jeff Russakow.

Without an international head, the three regional heads worldwide–Rose Tsou (Asia), Rich Riley (Europe) and Keith Nilsson (Emerging Markets)–have continued to report to Bartz. The U.S. region–Yahoo’s most significant market–is headed by Hilary Schneider.

Here is the Yahoo top management org chart, released back in February (click on it to make it larger):

On BoomTown’s recent grand tour of Europe, I paid a visit a week ago to London to moderate some sessions at Media Guardian’s Changing Media Summit 2009.

As in the U.S., a lot of the same questions were asked there about when and how the new media business would cross the Rubicon to transform into a strongly profitable and sustainable enterprise.

Via advertising? Subscriptions? Product placement?

“We’ve got to get to a place where we’re going to become an industrialized-sized business,” said one panelist at a session on monetizing such media, in what was a common question.

Well, considering how small the revenues in new media still are compared to traditional media, along with the recent negative impact of the econalypse, even a profitable popcorn stand would be an admirable achievement right about now.

Still, the room was packed at the Park Plaza Riverbank Hotel overlooking the Thames River and Big Ben, as people searched for answers.

One of the panels I moderated had the much-too-vaunted title of “The Future of Media: Capturing the Essence of Reinvention in the New Age.”

The panelists talked about what the media company of tomorrow looks like, as well as discussing the Next Big Thing.

The group included Ashley Highfield, managing director and VP, consumer and online for Microsoft (MSFT); Larry Kramer, former president of CBS (CBS) Digital and senior adviser to Polaris Ventures; Peter Smith, president of GE (GE) NBC Universal’s international unit; and Mike Volpi, CEO of video start-up Joost.

Here’s a video of interviews I did talking about all this and more while at the Guardian Media Group’s new digital-heavy offices in London.

It includes Volpi and Kramer, as well as Guardian-owned paidContent.org head Rafat Ali and the BBC’s tech news correspondent, Rory Cellan-Jones: