Constant Acquisition at Microsoft, and One Deal That Didn’t Close

With his impending departure as Microsoft’s chief executive, Steven A. Ballmer has put an expiration date on one of the most prolific deal-making streaks in technology over the last two decades.

But that career as a serial acquirer is notable as much for its misses as its hits. And the acquisitions have helped turn Microsoft into a gargantuan technology conglomerate that some investors regard as unwieldy, raising the possibility that Mr. Ballmer’s successor will sell businesses, not buy them.

During Mr. Ballmer’s 13-year tenure, Microsoft has purchased 149 companies, according to data from Standard & Poor’s Capital IQ. Most transactions were well under $1 billion. But some were certified blockbusters, notably the $8.5 billion acquisition of Skype in 2011 and the nearly $6 billion takeover of aQuantive in 2007.

With the deals, Microsoft moved into new business areas, from videomessaging to digital advertising to social networking. The new operations supplemented the software pioneer’s traditional strongholds, the Windows operating system and the Office suite of apps.

Should Mr. Ballmer’s successor choose to pick up the merger baton, he or she will have plenty of resources on which to draw. The company had $76.2 billion in cash and short-term investments as of June 30, a formidable war chest by any standard.

Some analysts contend that future Microsoft deals may go toward selling off businesses, however. One, Richard Sherlund of Nomura Securities, suggested in late May that the company could sell its Bing search engine or Xbox home entertainment division to focus on its core products.

Under Mr. Ballmer, Microsoft has also made a number of other investments meant to shore up strategic allies, including taking a nearly 18 percent stake in Barnes & Noble’s e-reader business and lending $2 billion to help support Dell Inc.’s sale to its founder.

And Microsoft joined Apple, BlackBerry and others in a collective $4.5 billion bid for patents held by the defunct Nortel Networks two years ago. The unusual move was meant to keep the cellular networking patents available to the entire industry, and trumped a competing offer by Microsoft’s archrival Google.

Some of those purchases appear to have borne fruit, at least for now. Microsoft has busied itself integrating Skype into core products like Windows. The videomessaging service has grown under its new parent, with $2 billion in sales expected for the current fiscal year, from about $800 million two years ago.

And Microsoft’s $1.2 billion takeover of Yammer last year allowed the company to add social networking to its corporate software offerings, while bolstering the service’s customer base to nearly eight million users from around five million.

But many of those deals have proved expensive follies. Last summer, Microsoft took a $6.2 billion accounting charge tied to its takeover of aQuantive, essentially writing off the acquisition of the digital advertising firm as a costly mistake.

And even today, Mr. Ballmer remains notorious for the takeover that he could not complete: the company’s roughly $45 billion bid for Yahoo. The Microsoft chief audaciously made a play for the Web pioneer in early 2008, calling a merger of the two “the next major milestone” in his company’s future.

The talks stalled for three months, during which Mr. Ballmer’s seemingly noncommittal approach frustrated advisers. He neither significantly raised his bid — he raised it $2, to $33 a share, though it remained a dollar below what Yahoo was willing to consider — nor did he go fully hostile.

And then he simply walked away, thanking Yahoo’s chief for his time.

Not all of the blame lies with Mr. Ballmer. Yahoo was persistent — too stubborn, in many investors’ views — in resisting Microsoft’s approach. And some shareholders were unhappy with the intercessions of Carl C. Icahn, a major Yahoo stakeholder.

But the shadow of that failed bid lingered for years, and Microsoft never again tried a conquest of that magnitude.