Japan's top mobile phone operator NTT DoCoMo Inc. said Friday its net profit rose nearly 12 percent in the first quarter, boosted by the growing popularity of smartphones. The nation's largest mobile carrier by subscriber numbers said net profit for the fiscal first quarter -- from April to June -- stood at 158.7 billion yen ($2.05 billion), up 11.7 percent from a year earlier. DoCoMo, whose smartphone lineup includes Samsung Electronic Co.'s Galaxy S, said it had 58.4 million subscribers at the end of June, adding 1.9 million from the same time of last year. The company sold 4.64 million mobiles phones during the three months, of which 1.3 million units were smartphones, it said. But more subscribers, including smartphone users, bought promotional packages that kept total revenues lower than last year, the company said. In the three months to June, operating revenues reached 1.05 trillion yen, down 3.9 percent from a year earlier, the company said. Operating profit rose 11.3 percent to 267.7 billion yen. The carrier said it will focus more on packaged sales of online data transmission, mainly for texting and gaming, and equipment sales revenues through "our efforts to strengthen sales of smartphones". In Japan's highly saturated mobile phone market, the carrier is ramping up efforts to grab a bigger slice of the expanding smartphone market led by Apple's iPhone, which in Japan is carried by rival Softbank.