­Mobile advertising agency, Millennial Media has raised an additional US$27.5 million in growth equity funding, with Bessemer Venture Partners, Columbia Capital, Charles River Ventures (CRV), and New Enterprise Associates (NEA) participating. This new investment brings the company’s equity funding to more than US$65 million.

The company is considered to be the largest independent mobile ad agency after larger rivals; AdMob and Quattro were brought by Google and Apple respectively.

Millennial Media is also planning to use the growth investment in part to build on its 2010 acquisition of TapMetrics, a mobile analytics company, with additional acquisitions in 2011. Additional investments will be made in the company’s international and platform lines of business.

According to Patrick Kerins, General Partner, NEA, Millennial Media continues to be one of their best-performing portfolio companies, and has achieved profitable results. The company has exceeded its revenue and EBITDA projections for ten consecutive quarters. As part of their growth equity strategy, they target companies like Millennial Media, as it has the seasoned management team, operational excellence and long-term vision to dominate the mobile advertising market.

The company’s US mobile ad network business reaches more than 85% of US mobile web users, serves more than 17 billion mobile ad impressions each month, and counts 18 of the top 25 Ad Age advertisers among its clients.

Millennial Media is headquartered in Baltimore, Maryland, has offices in New York, London, and San Francisco; with sales offices in Detroit, Los Angeles, Chicago, Dallas, and Atlanta.