Former Yahoo tech star Qi Lu (pictured here) is poised to take on the big job of being Microsoft’s top digital executive, according to several sources inside and outside the company.

The appointment could be announced by Microsoft as early as next Monday.

A variety of details is still being ironed out, though, including whether the well-regarded techie Lu will be “paired” with another executive at Microsoft (MSFT) with more general business experience.

While Lu has managed large teams while at Yahoo (YHOO) and also huge projects, he does not have advertising sales and media experience that will be a big part of his purview at Microsoft.

In that job, he will be the boss of three strong digital execs at the software giant: Satya Nadella, the SVP who heads engineering for Microsoft’s search, portal and advertising platform group; Yusuf Mehdi, whose online services portfolio includes marketing, online audience business development and product management for MSN and the search properties; and Brian McAndrews, the SVP for the advertiser and publisher solutions group.

That executive partner could be some higher-ranking Microsoft exec or even CEO Steve Ballmer himself.

Elevating McAndrews is also a possibility, as he has also wanted the digital chief job and could decide to leave after not getting it. (He also would not be a bad choice for Yahoo’s new CEO.)

McAndrews was the CEO of aQuantive, an ad company bought by Microsoft for $6 billion last year.

As I have previously written, Lu would be a different choice for the post than many had expected.

In picking a serious tech-oriented executive over a more media-centric one, a dichotomy that Ballmer has been puzzling over, according to several people with whom he has spoken, he is clearly staking out an even more head-on fight with Google (GOOG).

But since a lot of Microsoft’s future rests on winning in the search and search-advertising space and trying to catch up with its techtastic Silicon Valley archrival from way back in the race, Lu is also well suited for the position.

Lu was EVP of engineering for the Search and Advertising Technology Group at Yahoo, where he ran all development initiatives for its search and monetization platforms. He was at Yahoo for a decade.

Importantly, Lu will definitely be a draw in bringing in top talent to Microsoft, especially from Yahoo.

Microsoft already grabbed another top Yahoo search exec, Sean Suchter recently.

And it is reportedly in a competitive bidding war with Google right now for yet another top Yahoo engineer.

Ballmer (pictured here), who led the now-defunct takeover bid for Yahoo and who has indicated a strong interest in buying only Yahoo’s search assets, could almost be seen as bypassing it all by sucking the talent right out of the place instead.

That might be a good move, since Yahoo’s board, while under intense Wall Street pressure to do so, is still debating whether to strike a deal with Microsoft to sell off its search and search ad business for massive guaranteed ad revenues.

While board member Carl Icahn has been pushing that deal, others on the board are still dubious that decoupling search from Yahoo is the right strategic move and believe it could leave the company at the mercy of Microsoft.

Yahoo might already be, especially if it keeps losing critical engineering talent to Microsoft. Being able to convince talent like Suchter and Lu to switch is a very bad sign.

Before he left Yahoo earlier this year, Lu was on the staff of the IBM Almaden Research Center, and worked at both Carnegie Mellon University and Fudan University in China (he also got degrees from both places).

And, in the kind of cred Microsoft likes, Lu holds 20 U.S. patents.

He left Yahoo after becoming dissatisfied with all the turmoil there, quitting in June, without another job lined up.

There has also been speculation that Lu would take a position as CTO of Facebook or even return to China for a tech job.

The well-respected Lu certainly has a multitude of choices, but the chance to lead money-laden Microsoft’s digital efforts–as it suits up for battle with Google–has been perhaps too hard to resist.

BoomTown has been poking around to try to figure out who Ballmer would choose for the digital head, ever since the man who used to be in charge, Kevin Johnson, departed in July for Juniper Networks (JNPR), after the software giant’s takeover bid to buy Yahoo failed.

I raised Lu’s name in a post several weeks ago as Ballmer’s top choice.

Several people close to the situation say the aggressive CEO has been keeping the deliberations close to the vest.

On an interesting side note, another one of Lu’s reports at Microsoft would be Harry Shum, corporate vice president of Search Product Development, who was his classmate and friend at Carnegie Mellon.

Please see this disclosure related to me and Google.

Yesterday, based on sources, BoomTown reported, that Yahoo search exec Sean Suchter was headed to Microsoft.

Now it’s official. Here’s a Microsoft (MSFT) statement on the hiring of Suchter (pictured here), an important tech leader at Yahoo (YHOO), from Satya Nadella, SVP for Search, Portal and Advertising:

“We are very pleased to confirm that Sean Suchter will be joining Microsoft as the GM of our Silicon Valley Search Technology Center, working on Live Search. Sean will report into Harry Shum when he starts work on December 22. We look forward to welcoming him to Microsoft at that time.”

The talent grab from Yahoo is an interesting one, given that Microsoft has also tried to to buy Yahoo’s search and search ad business many times, to little success.

Microsoft CEO Steve Ballmer reiterated that desire yesterday at the software giant’s annual meeting, although he discounted the possibility that Microsoft would rebid for all of Yahoo after it abandoned a takeover attempt earlier this year.

His statement sent Yahoo’s stock further into the basement.

Losing important execs like Suchter, who was the VP of Search Technology at Yahoo, will also not help the company’s prospects. Suchter was deeply involved in Yahoo’s efforts to open up its search platform, initiatives the company has touted aggressively as a bright spot in its not-so-lustrous landscape.

Suchter–who came to Yahoo almost six years ago after it acquired Inktomi (the company that got Yahoo into the search business) in early 2003–has been talking with Microsoft for a while and his leaving was not linked to this week’s announcement that Yahoo CEO Jerry Yang will be stepping down.

But it could be linked to the possibility that another former major Yahoo search exec could also be going to Microsoft. I wrote a post earlier today that I thought the Ballmer was looking at Qi Lu–the well-regarded Search and Advertising Technology group EVP at Yahoo, who left earlier this year–to be its digital head.

All this muscling up in search by Microsoft is troubling for Yahoo. There are big questions, now that Yang is stepping down, whether Yahoo will stay in the search business or sell it off. Yang has been a big proponent of doubling down in search, considering it integral to the entire Yahoo ecosystem.

But others make the very persuasive argument that Yahoo will be increasingly outspent by both Google (GOOG) and Microsoft, in what is turning into a very vicious and expensive arms race.

If it sold off its No. 2 search business to Microsoft–ironically, Yahoo used to deliver Microsoft’s search results–many think it could have huge costs savings and garner guaranteed revenues.

News of Suchter’s departure from Yahoo, including the internal memo announcing it, appeared in Valleywag yesterday.

Please see this disclosure related to me and Google.