Cellular phone operator Bharti Airtel of India is one of four companies facing fines in Nigeria for poor service. The companies have until May 21 to pay the regulators or they will face further penalties. Image Credit: Reuters

Google will invest $700 million in India's No. 2 mobile-phone operator, deepening its push into in the world's second-largest wireless market.

Alphabet Inc., that owns the Google search engine, will acquire a 1.28% stake in Bharti Airtel Ltd. at 734 rupees ($9.8) per share, according to an exchange filing from Bharti Friday. An additional $300 million will be toward multi-year agreements, it said.

Asia's third-largest economy and its almost 1.4 billion population presents an attractive opportunity for the technology giant, whose Android software competes with Apple Inc. for global operating system dominance. The country is a key growth market for Google's search and advertising businesses as well as for others such as Facebook Inc., Amazon.com Inc. and Netflix Inc. as the only billion-people-plus country that's still open to foreign firms. Google had previously invested in billionaire Mukesh Ambani's digital unit.