Yahoo is launching a search for a successor to Jerry Yang, but analysts say the executive most likely to call the shots in the long run is… Steve Ballmer.

In a research note, UBS analyst Benjamin Schachter noted that speculation on likely candidates centered on names like Yahoo President Susan Decker, News Corp. President Peter Chernin, former AOL Chief Executive Jonathan Miller and former eBay Chief Executive Meg Whitman.

Still, the ultimate power broker is likely to be Mr. Ballmer, the chief executive of Microsoft.

We still believe Microsoft will eventually own Yahoo, Mr. Schachter said. “Jerry moving out of the CEO role may accelerate this.”

Microsoft, in a bid to challenge Google’s dominance of online search and search advertising, offered $44.6 billion on February 1 to acquire Yahoo. In June, after failing to reach an agreement, Microsoft said it was “walking away” from its pursuit.

Even if Yahoo is not acquired outright, the analyst said the company could restructure or cut a deal with News Corp., Time-Warner, Google or Microsoft.

Mr. Yang, who co-founded Yahoo with David Filo, was recruited to become the CEO in June 2007. He followed former movie industry executive Terry Semel, who was deposed after failing to recapture the company’s early growth.

Another key player in the post-Yang era is likely to be billionaire investor Carl Icahn. Mr. Icahn, who controls almost 69 million shares, mounted a proxy fight in an effort to clinch a buyout deal with Microsoft. Ultimately, Mr. Icahn backed off the effort to oust the board in exchange for board seats for himself and two allies and an agreement that he would have a role in future buyout negotiations.