Microsoft Corp is considering Ericsson AB Chief Executive Hans Vestberg as a possible successor to outgoing CEO Steve Ballmer, Bloomberg cited sources briefed on the software giant’s executive search as saying on Wednesday.

Bloomberg did not report on whether the company has reached out to Vestberg, who as CEO of the Swedish firm runs one of the world’s largest telecommunications equipment makers.

His naming may come as a surprise to many on Wall Street.

Analysts have discussed potential candidates ranging from company insiders Satya Nadella and Tony Bates to several outsiders. But speculation refocused on internal choices this month after leading external candidate, Ford Motor Co CEO Alan Mulally, took himself off the list.

Sources familiar with the company have told Reuters that, with Mulally out of the running, the list of candidates able to run a globe-spanning software corporation struggling to expand into the mobile software and devices markets was thin.

Analysts say Microsoft may have to look at “dark horse” candidates, but noted that some widely reported tech sector candidates, including Pivotal Inc CEO Paul Maritz, have already declined to take the job.

In a blog post on the company’s website in December, Microsoft’s lead independent director John Thompson, who is spearheading the search, emphasized the need for a CEO with good tech credentials and “an ability to lead a highly technical organization and work with top technical talent.”

Reuters could not immediately verify Bloomberg’s report, and Ericsson was not immediately available for comment.

Microsoft declined comment. A source close to the company has said no CEO appointment was likely until the last week of January or February.

(Reporting by Edwin Chan; Editing by Eric Walsh and Kenneth Maxwell)