David Ko (pictured here), head of Yahoo’s mobile division, has added the Internet giant’s vast media properties in the U.S. to his portfolio, according to several sources.

BoomTown recently reported that Ko was the likely person to take over as North American Audience head at Yahoo (YHOO), reporting to U.S. EVP Hilary Schneider.

With purview over programming and more for the main Yahoo media properties, such as News and Finance, he fills a slot left by the departure of Jeff Dossett in May.

Since then, the key Yahoo content division has been run jointly by Jimmy Pitaro, who heads Vertical Audience Experiences for Yahoo, and Tim Mayer, who is in charge of Search & Social Applications, as well as the powerful homepage of Yahoo. Both now report to Ko, who joined Yahoo in 2000, sources said.

But, in a related move, product development for mobile has moved from under Ko to CTO and EVP of Products Ari Balogh.

A similar move of Yahoo’s media properties took place earlier this year, shifting key tech development responsibility to a global product organization at Yahoo’s HQ in Sunnyvale, Calif.

Previously, as had been the case in mobile, such development had been mostly carried out by individual media properties.

The argument for the shift posits that centralizing product development of Yahoo offerings drives efficiencies, saves money, eliminates redundancies and accelerates growth around the world.

Those who do not like the idea think it is wrong to separate the development of a product from programming because the two are intricately dependent and need to be tweaked delicately.

But, said one source, mobile has been deemed by CEO Carol Bartz as “part of the core” at Yahoo instead of more an experimental offering as it has been viewed internally.

Thus, mobile apparently needs to be closely aligned to all product development going forward.

Ironically, one of Yahoo’s more high-profile mobile efforts, its Yahoo Go mobile software application and portal, which was launched to much fanfare at the Consumer Electronics Show in Las Vegas almost four years ago, will be shuttered Jan. 12, 2010.

Now, under Ko, Yahoo’s mobile efforts have been centered around building apps for smartphones, although that market has become increasingly dominated by players such as Apple (AAPL) with its iPhone, Google (GOOG) and its Android effort and many others.

Google also just bought an innovative mobile advertising company, AdMob, which gives it a headstart in this nascent arena.

Without its own device and a dominating strategy, Yahoo must use its Web heft to push its content into the mobile space.

Presumably, that is the thinking behind giving Yahoo’s mobile and media properties the same boss.

Ko, who has worked in a variety of areas at Yahoo, took over as SVP of Yahoo Mobile after Marco Boerries left in late February as EVP of the Connected Device Division, which now does not exist under that name.

He had run Yahoo’s mobile business in the Asia Pacific region.

According to Ko’s Yahoo bio, he previously worked at Salomon Smith Barney as a senior associate and analyst. He is a graduate of New York University’s Stern School of Business.

Ko, who lives in San Francisco with his family, the bio notes, inexplicably “enjoys reading tech blogs.”

Well, then, Dave, we hope you have enjoyed this post!

Yahoo CEO Carol Bartz is making the most substantive changes in her exec ranks since she did a massive restructuring of its staff in late February, according to sources close to the situation.

“She is continuing to clean the place up,” said one top exec about the moves, which are likely to be announced internally tomorrow.

Among the shifts in management will be filling the slot left by the departure of North American Audience head Jeff Dossett in May.

UPDATE: Sources say Yahoo’s head of mobile, David Ko, will get the job of top Audience exec, although it is not clear if he will have the same portfolio has former media heads at Yahoo.

Since Dossett left, his job has been split between Jimmy Pitaro, who runs Vertical Audience Experiences, and Tim Mayer, who is in charge of Search & Social Applications. They both currently report to U.S. EVP Hilary Schneider.

The job of Audience head is a key role, given that Yahoo’s powerful media properties are among its most valuable assets. In recent months, Yahoo has made some major changes in the way it creates its juggernaut News property.

Also to be filled is the job being done by Corporate Partnership SVP Jim Schinella, who, as BoomTown previously reported, is set to leave at the end of the year.

I could not determine who will take Schinella’s job, inside or out.

Interestingly, Yahoo has yet to name an international head.

Sources said the company had filled the position, using a headhunter, but the London-based media exec candidate backed out at the last minute. That meant Yahoo had to restart its search.

There might also be other top exec changes, all part of Bartz’s consolidation of power at Yahoo. She has named a spate of new top execs from outside, but has also kept some from the regime of former CEO and co-founder Jerry Yang.

These staffing moves have come even as a stream of execs continued to depart the Silicon Valley Internet giant, including, most recently, Mike Walrath, who was SVP of advertising strategy. Walrath had led Right Media, the online ad exchange Yahoo bought for $680 million in 2007.

Walrath was widely expected to leave Yahoo in July, at the completion of his earnout from the acquisition, sources said, so the move was more sudden than expected internally.

Sources noted that Bartz moved Walrath’s departure forward in order to announce a new strategy for Right Media focused on premium publishers and to dump those ad networks and publishers of lesser ilk.

Whether this will stop the competitive onslaught in the ad exchange space is an open question given that Google has entered the fray significantly and that Facebook is widely expected to bolster its efforts.

Lastly, several sources said that there are also likely to be more changes on Yahoo’s board, which has seen the departure of two members recently.

In September, Maggie Wilderotter said she would leave the board by year’s end. And former Yahoo nemesis and investor Carl Icahn left the board in late October.

Whether Yahoo will replace them or keep its current size of 10 directors is not clear.

Also possible, several sources said, would be Bartz taking the chairman title, which is currently held by Roy Bostock. Bostock, along with Yang, played a key role in its botched takeover battle with Microsoft (MSFT).

Bartz finally successfully struck a sweeping search and advertising partnership with the software giant this summer, which is moving closer to being launched.

Yahoo’s SVP of North American Audience, Jeff Dossett, is leaving the company.

Reasons for the departure are personal, said sources, who said that Dossett (pictured here) is most likely to do a start-up.

Dossett did not return emails asking for comment, but Yahoo (YHOO) confirmed the departure to BoomTown.

It was announced internally that Dossett has resigned and his responsibilities have been assumed by Jimmy Pitaro, who runs Vertical Audience Experiences for Yahoo, and Tim Mayer, who is in charge of Search & Social Applications. They will jointly lead the North America Audience business, reporting to U.S. EVP Hilary Schneider.

Dossett has been in charge of all of Yahoo’s media assets, including its powerful News, Sports and Finance content sites.

He has been rejiggering the media unit since he arrived last year, including centralizing product development.

Dossett joined Yahoo last November, coming to the company from Microsoft (MSFT), where he was MSN executive producer and general manager.

In his job at MSN, Dossett was the lead for audience, content and programming strategy and execution in the U.S.

He had worked at the company since 1991, in a variety of sales and marketing jobs in Canada, and later worked on strategy and business development for MSN.

Dossett was also CEO of Carpoint, now MSN Autos, and was GM of its real estate arm.

He also took two years off from Microsoft in 2002 to climb the highest mountains on each of the seven continents, finally reaching the summit of Mount Everest in May of 2004.

Dossett reached the summit of Everest again for a second time last year.

[UPDATED: With Hearst press release confirming the move at the bottom.]

Neeraj Khemlani (pictured here), Yahoo’s general manager and executive editor of news, is set to leave his job–right in the midst of a major restructuring of its media unit–to work at Hearst Corp.

Khemlani’s departure was announced to his staff at Yahoo (YHOO) today and confirmed by the press release from Hearst below.

While Khemlani was in line to head one of the three main prongs of the new content organization, running a possible network programming arm, sources inside and outside Yahoo said he instead has opted to take a job as VP and Special Assistant to the CEO for Digital Media at Hearst.

Khemlani is not leaving due to the upcoming changes at Yahoo, said sources, but because he got a “compelling” offer to work for a more traditional media company in a range of businesses, from newspapers and magazines to broadcast, helping turbocharge their digital efforts.

Khemlani, who came to Yahoo from a long stint as a producer at the television news show “60 Minutes,” will be reporting to the privately-held media company’s vice chairman and CEO, Frank Bennack.

Khemlani, several sources said, told his bosses at Yahoo–U.S. Audience head Jeff Dossett and U.S. EVP Hilary Schneider–on Friday of his plans right when the pair were in the midst of planning a major shift in how media are managed and created at Yahoo.

At Hearst, he will be a resource for its many divisions, which all have their own digital operations, and he will be based in New York. (Khemlani currently has been working out of Yahoo’s media offices in Santa Monica, Calif.)

In a press release from Hearst, Bennack said: “Hearst’s major operating groups have all made substantial progress towards our corporate objective of fully participating in the digital transformation. The creation of this new position is designed to accelerate the progress through greater cooperation and synergy across divisional lines. Neeraj is uniquely equipped to help me and my colleagues realize that goal.”

Ironically, Hearst has a strong relationship with Yahoo, as a content partner.

UPDATE: In a Hearst press release Khemlani said: “I am delighted to join Hearst Corporation. We are witnessing the reemergence of content and media driving value in the new world and Hearst is uniquely positioned to realize that value across multiple digital platforms and distribution points. Remember, we’re only in the second inning of the Internet. Hearst, with all its assets and investments, expects to take a commanding lead by the seventh?inning stretch.”

As BoomTown reported yesterday, the management of the media unit is about to be rejiggered dramatically.

It’s part of big changes coming for Yahoo, including an even more massive management reorganization that new Yahoo CEO Carol Bartz could announce this week, as this column reported on Friday.

Under a plan being considered, the media unit will be split into three parts: vertical programming, network programming and search monetization.

This comes after some other recent changes in the way media product development is done–moving to a centralized global structure, rather than residing in individual media units–which was also reported here last week.

Now, if they go through with current plans to reorganize the media unit, Schneider and Dossett must find another head of network programming.

Several inside sources said that vertical programming will probably roll up under current Sports GM Jimmy Pitaro. And Tim Mayer–who is now VP of search monetization and distribution–would probably remain in his job, with perhaps even more monetization duties added.

Here is the Hearst press release about Khemlani:

HEARST CORPORATION NAMES NEERAJ KHEMLANI VICE PRESIDENT & SPECIAL ASSISTANT TO CEO FOR DIGITAL MEDIA

Hearst Corporation (www.hearst.com) is one of the nation’s largest diversified media companies. Its major interests include ownership of 16 daily and 49 weekly newspapers, including the Houston Chronicle, San Francisco Chronicle and Times Union; as well as interests in an additional 43 daily and 72 non?daily newspapers owned by MediaNews Group, which include the Denver Post and Salt Lake Tribune; nearly 200 magazines around the world, including Good Housekeeping, Cosmopolitan and O, The Oprah Magazine; 29 television stations through Hearst?Argyle Television (NYSE:HTV) which reach a combined 18% of U.S. viewers; ownership in leading cable networks, including Lifetime, A&E, History and ESPN; as well as business publishing, including a minority joint venture interest in Fitch Ratings; Internet businesses, television production, newspaper features distribution and real estate.

Besides the more massive management reorganization that new Yahoo CEO Carol Bartz could announce this week, as BoomTown reported on Friday, the Internet company’s powerful media arm might also see a drastic shift in management structure even sooner.

According to several sources inside the company, U.S. Audience SVP Jeff Dossett (pictured here) has been working on the changes for a while, part of an overall change in how Yahoo (YHOO) makes and delivers content. The new organization could be announced this week too.

Under a plan being considered, the media unit will be split into three parts: Vertical programming, network programming and search monetization.

It is not clear under this new set-up if Yahoo will keep its more traditional structure of having powerful general managers, each in charge of its big properties.

But that seems likely to be scaled back, at the very least, since the shift in management comes after some major recent changes in the way content is made, as was also reported here last week.

Already, the media group’s product development for all its major properties–such as News, Sports and Finance–is set to be moved to a central global product development organization at Yahoo’s HQ in Sunnyvale, Calif.

Until now, such development has been mostly done by individual media properties, many of which are located down south, in Santa Monica.

The argument for the shift posits that centralizing the product development of a Yahoo media offering drives efficiencies, saves money, eliminates redundancies and accelerates growth across the world.

Those who do not like the idea think it is wrong to separate the development of a product from the programming because the two are intricately dependent and need to be tweaked delicately.

Dossett will remain overall head of media efforts, but there is a lot of speculation inside the group about who will head the three new parts of media unit. But that is still being worked out by Dossett and his boss, U.S. head Hilary Schneider, and is still not decided.

But several inside sources said that vertical programming is probably a lock to roll up under current Sports GM Jimmy Pitaro.

Former “60 Minutes” producer and News GM Neeraj Khemlani seems be the most likely candidate to head network programming, but that is not yet complete.

And Tim Mayer–who is now VP of search monetization and distribution–would probably remain in his job, with perhaps even more monetization duties added.