He added: "Our overall performance in Europe and Africa remained strong during the third quarter, reflecting good execution".
Vodafone warns of a hard year, amid slow third and fourth quarter revenue results.
Britain also remained tough for Vodafone, with service revenue declining 3.2 percent, which it said reflected increased competition in enterprise, an area of strength for the operator. In Europe, service revenue growth continued, led by Italy, Germany and Spain.
"As announced earlier this week, we have also entered into discussions with the Aditya Birla Group about an all-share merger of Vodafone India and Idea", Colao said.
Vodafone confirmed its outlook for the year, saying it expected to meet the lower end of its forecast for earnings before interest, taxes, depreciation and amortization. This followed a €5 billion write-down of Vodafone's Indian unit previous year.
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The figures Toyota released say overseas production increased 2.1% past year to 6.17 million cars, with growth in North America. It held the number one title in 2011 after Toyota's production was hit by a massive quake and tsunami in north-eastern Japan.
Vodafone expects the business to decelerate in the fourth quarter due to intense competition from Reliance Jio's free offers.
In a third quarter trading update, the mobile network operator (MNO) revealed that its reported United Kingdom revenues declined by 19% year-on-year in the three months to €1.72bn (£1.47bn), while its organic service revenues were down 3.2% to €1.6bn. Idea is the nation's third largest mobile operator while Vodafone has second place. Jio unleashed a price war by offering free voice and data since starting services in September, severely denting the financials of its rivals.
This weaker performance overshadowed a stronger performance elsewhere, as it saw organic service revenue up 4.0% in its South African business Vodacom in the quarter, and 10.5% in its other markets in the region, helped by a strong performance in Turkey and Egypt.
In India, the service revenue for the firm declined by 1.9 per cent, which it said was "driven by heightened competitive pressure following free services offered by the new entrant and the adverse impact of demonetisation on prepaid top-up volumes during the quarter".
Overall Vodafone Group's revenue declined by 3.9 per cent 13,687 million euros (around Rs 99,504 crore) from 14,247 million euros (around Rs 1,02,749 crore) during period under review.