Mobile phone giant Vodafone added a net 4.1 million new users in its first quarter to 30 June, ahead of forecasts and up 35% on a year ago.
Arun Sarin (centre) says Vodafone must improve in Japan
Global subscribers now totalled 165 million, boosted by growing markets such as Spain, Italy and Romania.
However average revenues per customer slipped in the UK and Germany, and fell in the tough market of Japan.
Vodafone signed up 1.1 million new 3G users in the quarter, taking total registered 3G users to 3.3 million.
"We have seen strong performances across Europe and in the US, and we continue to focus on improving our business in Japan," said Arun Sarin, chief executive of Vodafone.
"3G is building momentum with over one million more registered devices in the quarter."
In Japan, Vodafone is third-ranked behind locally-based competitors NTT DoCoMo and KDDI.
Although Vodafone Japan recorded 5,000 net new customers in the month of June, it posted a loss of 72,000 over the quarter.
In the UK, Vodafone added a net 165,000 customers in the quarter, giving it 15.5 million users. Average revenue per user (ARPU) dipped to £300 for the year to June from £306 for the year to March, mainly because of regulatory price cuts in termination rates.