Safaricom Ltd., East Africa’s biggest mobile phone company, headed for the lowest close in 14 months on speculation a plan by Bharti Airtel Ltd.’s local unit to cut fees will start a price war.

The stock of East Africa’s biggest company by market value fell as much as much as 6.7 percent to 4.20 shillings before trading 5.6 percent lower at 4.25 shillings as of 11:43 a.m. Nairobi time. A close at this level would be the lowest since November 2009.

“It is investor anxiety over the escalation in price wars,” Gregory Waweru, a research analyst at Nairobi-based Kestrel Capital East ASfrica Ltd., said in a phone interview today. “Investors are waiting for Safaricom to respond to the cut in Airtel’s tariffs”.

The stock has fallen for three consecutive days after Airtel Kenya Ltd., announced a 67 percent reduction in the cost of its calling rates on Jan. 13.

Mobile operators in Kenya are becoming more reliant on data for revenue after the industry regulator in August halved the rates that operators charge each other to connect voice calls across networks to 2.21 shillings ($0.03). That triggered a round of cuts in call costs by companies to less than 2 shillings a minute and in some cases free calls during off-peak hours.