Millicom, which specialises in operations in emerging markets in Asia, Africa and Latin America, has another operation, Paktel, as it main unit in Pakistan.
"Millicom is currently negotiating the sale of its share in Pakcom, its second operation in Pakistan," the group said in a statement as it announced its third-quarter results.
The firm's Chief Executive Marc Beuls told Reuters that talks on a sale had just started and that completion of a deal was likely during 2006.
Millicom reported earnings before interest, tax, depreciation and amortisation (EBITDA) of $110.8 million, slightly higher than expectations of $108 million, but below the $117.6 million of the same period of 2004.
Its shares were 3.09 percent higher at 150 crowns after the figures.
Millicom said its growth would have been higher without Pakcom and that it had decided to concentrate its investments in one operator in the country. It said Paktel had 945,000 subscribers by the end of the third quarter.
Key players in the Pakistan market are market leader Mobilink, run by Egypt-based regional telephone operator Orascom Telecom, and Ufone - a wholly owned subsidiary of state-run Pakistan Telecommunication Co Ltd.
Millicom said that it added 707,000 net new clients across its operations in the third quarter, which ended with it having 6.4 million subscribers.