Research by analyst firm Ovum showed that mergers in the global telecoms market fell from a high of 67 transactions in 2007 to 21 transactions in 2014. M&A activity did pick up again in 2013, as a result of 15 new acquisitions in the Asia Pacific region and six new acquisitions in Eastern Europe. M&A activity was also higher in 2014 than in 2012 due to AT&T's purchase of a 100 per cent stake in Leap Wireless in the U.S. in March 2014, Bharti Airtel's purchase of Warid Congo in May 2014, and Hutchison Whampoa's takeover of O2 Ireland in May 2014. Meanwhile the research company also found that China Mobile is the largest mobile group globally in terms of proportionate subscriptions, followed by Vodafone in second place and India's Bharti Airtel in third. Report