Vodafone Group shares rose the most in 14 months after the wireless carrier reported a smaller decline in service revenue than analysts estimated, showing signs of recovery in European markets.
In Ireland, Vodafone said its customer base grew 7.6pc in the year to the end of September. Almost two-thirds of customers here use smartphones, and use of mobile data increased by 55pc in the year, Vodafone said.
The company has 2.3 million Irish customers: the over whelming majority are mobile users.
Vodafone stock is the most commonly held of any company in Ireland, a legacy of Vodafone's use of shares to fund the acquisition of the old Eircell mobile phone business.
Yesterday Vodafone said service revenue, the money Vodafone gets from customers' plans and traffic on its network, fell 1.5pc in the last quarter, excluding currency swings and acquisitions.
It compared with the average 2.6pc decline predicted by five analysts surveyed by Bloomberg. Earnings also beat analysts' estimates.
The numbers underscore the early results of Vodafone's £19bn (€24bn) network-improvement programme to entice customers to spend more on web surfing and video downloads. Vodafone is the latest European carrier to show improvement after years of price wars, as rivals from Germany's Deutsche Telekom to France's Orange also exceeded estimates for the latest quarter.
"You have further weight to the theme that European wireless is recovering," said Guy Peddy, an analyst at Macquarie Research in London. As more carriers report better-than-expected results, "it's more of a stampede".
The shares rose as much as 6.3pc to 221 pence, the steepest increase since August 29, 2013, the day Vodafone said it was in talks to sell its stake in Verizon Wireless to US partner Verizon Communications. The $130bn (€105bn) transaction was completed this year.
Vodafone shares added 6.1pc to reach 20.55 pence by midday yesterday. Vodafone announced the spending boost, called Project Spring, a year ago and since then it has rolled out more high-speed fourth-generation mobile and fibre-broadband infrastructure. The project will run through 2016.
Customers "are showing an increasing propensity to trade up to bigger data allowances as a result of the 4G experience," Vodafone said. Still, only 6pc of its European customers are using 4G, which allows faster web access and video streaming.
Vodafone also saw less of an effect from mobile termination-rate cuts - regulators' limits to what carriers can charge to complete a call from a customer on a different network.