Shares in Millicom International Cellular SA (Nasdaq: MICC) -- a key player in emerging markets -- plummeted by more than 25 percent today following an announcement from the company that it has ended talks with a potential buyer, understood to be China Mobile Communications Corp. . (See Millicom Ends Sale Talks.)

Millicom’s stock had risen by 55 percent this year on the back of takeover talks, and today's drop has shaved around $1.4 billion off the company's market value. Shares in the company were down 25.12 percent (11.41) to $34.02 in morning trading on the Nasdaq , recovering from a low of $31.71 at one point.

Millicom was widely expected to accept an offer of around $5 billion in what would have been China Mobile’s first major overseas acquisition, but has apparently decided that wasn’t enough.

In its statement, Millicom said that after “prolonged discussions,” it “has now concluded that this purchaser will not be in a position within an acceptable timeframe to make a binding offer that is suitably attractive, given the current strong performance of the business, or sufficiently certain of closing.”

That calculation reflects the growing importance of emerging markets, as carriers seek to expand beyond their domestic playgrounds and tap into soaring mobile subscriber growth in countries that lack fixed telecom networks. At the end of March, Millicom had more than 9 million subscribers in 16 countries across Africa, Asia, and Latin America, a 52 percent increase compared with March last year.

There have been several similar deals this year, including MTN Group Ltd. Ltd.'s $5.53 billion acquisition of Dubai-based Investcom Holding , Maxis Communications Bhd. ’s $1.08 billion takeover of Aircel Ltd. in India, and Celtel International B.V. ’s purchase of Vmobile in Nigeria for $1.005 billion. Investcom withdrew its own $5 billion-plus offer for Millicom when it was acquired by MTN. (See Maxis Snaps Up Aircel, MTN Buy Energizes EMEA M&A, and Emerging Markets See More Mobile M&A.)

Millicom has no lack of suitors, having announced in January that it was enlisting Morgan Stanley to help it consider “a high number of unsolicited approaches.” (See Millicom Examines Bids.)

"This one's off the table for now but it will return at some point in the future, either in the form of a different offer from the same bidder or a different bidder altogether,” says Patrick Donegan, senior analyst for wireless at Heavy Reading. “In the meantime, in the sort of markets that it specializes in, Millicom can continue operating independently for some time."

Other companies that have expressed interest in Millicom include Egyptian carrier Orascom Telecom , Kuwait's MTC-Vodafone , Telenor Group (Nasdaq: TELN), and América Móvil S.A. de C.V.

— Nicole Willing, Reporter, Light Reading