Orascom Telecom Holding SAE slid probably the most in much more than two months as Chairman Naguib Sawiris said the biggest mobile-phone operator in the Middle East by users probably won’t be able to resolve its tax dispute with Algeria.

The shares lost 4.3 percent, the most since Oct. 27, to 4.26 Egyptian pounds at the 2:30 p.m. close in Cairo, valuing the firm at 22.4 billion pounds ($3.8 billion). Egypt’s benchmark stock index dropped 3.1 % as foreign investors exited its northern border African marketplace after two men set on their own fire in Egypt, one who should later die, emulates a Tunisian man whose work sparked violent protests against unemployment and corruption in Tunisia.

“We had no reply from the Algerian government,” Sawiris said. “They have not contacted us. They've not sat around. They've not allocates a bank to value the business. I’m not optimistic.”

Sawiris, speaking these days in the Egyptian Red Sea resort of Sharm El-Sheikh, said he was getting ready to seek arbitration from the government from the North African country, which has slapped Orascom’s division there through further than $800 million in backdated taxes. The firm says the insisted are unjustified.