Qatar, eager to boost its footprint in Turkey, has made a takeover approach to the majority owner of Oger Telecom, which owns a controlling stake in Turk Telecom, sources said.

Qatar has directly approached Saudi Oger - owned by the family of late Lebanese prime minister Rafik Al-Hariri - for its approximately 55 percent stake, the sources said.

By acquiring the Oger Telecom stake, Qatar would also get Turk Telecom and its mobile unit Avea as well as South African operator Cell C in which Oger holds a 75 percent stake.

Putting a price on the entire deal is difficult because Cell C, South Africa's third largest operator, is unlisted but the Turk Telecom stake alone would be worth at least $8.6 billion according to Reuters data.

Turk Telekom is one of the biggest listed companies in Turkey with has a market cap of $15.6 billion.      Any deal could be complicated by Saudi Telecom Company (STC), which has a 35 percent position in Oger Telecom and first refusal should the stake come up for sale, up to a certain price.

"It's a complicated deal but the Qataris have shown their interest by going to the family straight. Going by the strength of their wallet, this is something they could pull off," one of the sources said.

"There is no guarantee that the approach will lead to a deal given heightened execution risk due to market volatility," one person familiar with the situation said.

Saudi Oger declined to comment. STC officials did not respond to requests for comment. Credit Suisse, acting on behalf of Qatar, declined comment.

"Qatar is not the only potential solution here. Saudi Oger has options with other people," another person familiar with the matter said, referring to Saudi Telecom, which he said could be forced to react.

Mandates for the transaction went out in the second half of 2010, the sources said, adding completing a deal would take time given the complexity of the ownership and transaction structure.

Saudi Oger has hired Citigroup and Deutsche Bank, according to the banking sources who declined to be identified as the matter has not been made public yet.

STC, which bought its current stake in Oger Telecom for $2.6 billion in 2008, is being advised by Goldman Sachs. - Reuters