InMobi, an independent mobile Ad network, and Softbank Corporation has completed a $200 million (N30 billion) investment agreement. The funding according to the agreement will take place in two tranches of $100 million in September 2011, followed by an equivalent tranche in April 2012.

With this agreement, Softbank joins existing investors; Kleiner Perkins Caufield & Byers and Sherpalo Ventures in helping InMobi become a global leader in the mobile advertising industry.

The $200 million investment, one of the largest to date in the mobile internet space, will help the company create value across the mobile ecosystem globally through world-class advertising, mobile payments using SmartPay, and HTML5 rich media production and distribution using the recently acquired Sprout™ platform.

Naveen Tewari, Founder/CEO of InMobi, said the size of the investment and quality of investor validates the enormous potential in mobile today and strengthens its role in helping the industry to grow.

“We have already established ourselves as a leader in mobile advertising on every continent.  This is just the beginning. With a global leader like Softbank behind us, we are now well positioned to fully capitalize on the opportunity before us through substantially increased product innovation, deeper market penetration, and acquisitions across the mobile ad value chain.”

According to Masayoshi Son, Chairman and CEO of Softbank, “I am delighted at this opportunity to partner with InMobi, one the world’s largest mobile ad networks.

I hope the partnership with InMobi, a fast-growing startup with significant mobile expertise and an outstanding technology platform; will further accelerate the pace of development in the mobile Internet space globally. We believe this partnership will help Softbank become the No. 1 Internet company in Asia and I look forward to working with the InMobi team.”

This partnership he continued will provide Softbank and InMobi with opportunities to further explore global scale collaboration in the fast growing mobile ad market. He noted the partnership is also expected to generate further synergies between InMobi and Softbank, given the significant number of prominent Asian Internet companies in Softbank’s investment portfolio.

John Doerr, Managing Partner, Kleiner Perkins Caufield & Byers, said: “InMobi is a rapidly growing company in one of the most explosive technology sectors.  InMobi delivers extraordinary value to publishers and advertisers globally. They are a leader in the mobile advertising revolution.”

Ram Shriram, Founder of Sherpalo Ventures added: “InMobi joins a select set of companies globally that have achieved massive scale in a short period of time. This investment is a strong validation of the mobile opportunity across the globe and InMobi’s ability to exploit to its full potential. Mobile and Smart Phones are changing the world for consumers, businesses, advertisers and publishers.” He said.