SEOUL (Reuters) - South Korea's SK Telecom Co said on Thursday it was not planning to buy a controlling stake in any major U.S. mobile carrier, brushing off earlier reports that it was eyeing Sprint Nextel Corp .


Shares in SK Telecom, South Korea's top mobile company, have fallen since cable news CNBC reported on Tuesday that SK was negotiating to buy Sprint, the No. 3 U.S. mobile service.

Investors fear uncertainties from a possible deal in the United States, where SK already posted sizeable losses over its mobile joint venture with EarthLink Inc , analysts said.

Sources familiar with the matter have told Reuters that SK and Sprint were in preliminary talks about collaborating on technology and said there were no acquisition talks.

"We are studying various business opportunities in the United States but are not seeking to take control in (any) major U.S. mobile operator," SK, which had initially declined to comment, said in a filing to the local exchange.

It did not elaborate and company officials declined to comment when asked about partnership or small-scale investments.

The Korea Exchange earlier on Thursday requested SK to clarify media reports about the acquisition talk.

SK, which controls about half of the South Korean mobile market, is seeking growth overseas as competition intensifies in the saturated domestic market.

But Sprint, which has been struggling to stem customer losses, already rejected a $5 billion investment by SK and a group of private equity firms last year, sources previously said.

SK Telecom fell 1.1 percent to 179,500 won on Thursday, against the benchmark Seoul index's 1.2 percent gain. The stock shed 2.7 percent on Wednesday.

SK agreed in late June to sell its money-losing U.S. mobile unit, Helio, for $39 million in stock to Virgin Mobile USA and to invest $25 million in Virgin Mobile.

(Reporting by Rhee So-eui; Editing by Keiron Henderson)
Copyright 2008 Reuters.