Five9, a provider of hosted call center software, announced it has raised $8.6 million in equity funding led by Adams Street Partners. Existing investors Hummer Winblad (News - Alert) Venture Capital and Partech International also participated in the round.

With the new capital, the total funding offered for Five9 during the three-year period becomes $37 million. During this period, Five9 (News - Alert) has tripled its revenue and customer base. The new capital will be used to further accelerate the company’s growth, according to company officials.

Five9 revolutionizes call centers with its cloud-based call center software solutions. With this software, the company solves an otherwise difficult problem of handling extremely high volumes of real-time telephone conversations in the cloud, for mission-critical business applications.

The company processes over one billion telephone calls per year for tens of thousands of call center agents worldwide. The Virtual Call Center from Five9 has now emerged as leading cloud-computing based call center software on the market.

 “As more and more enterprise call centers are shifting away from premise-based solutions and toward cloud-based solutions like Five9, we are uniquely positioned to capture a growing share of this market. This new capital allows us to accelerate that effort,” said Mike Burkland, CEO of Five9, in a statement.

“As we continue to grow, we are delivering ever-increasing benefits to our customers: lower costs, improved productivity and streamlined operations from deploying a cloud-based call center solution,” Burkland added.

Five9 also won several indus

try accolades for achieving continued growth. The company was named Inc. magazine’s list of America’s fastest-growing private companies last year. In another such endorsement, the company was also named to the San Francisco Business Times’ list of 100 fastest-growing private companies in the San Francisco Bay Area.

According to David Welsh, partner, Adams Street Partners, Five9 has demonstrated tremendous technical capability combined with prudent financial management that has produced sustained profitability through periods of high revenue growth and increasing market share. “We are excited to be a partner with Five9 as enterprises increasingly turn to cloud-based call center solutions.”

Five9 claims to be the largest pure-play SaaS (News - Alert) provider to the call center market. The company constantly strives to enhance its call center product portfolio based on market demand, customer and partner feedback.

The cloud-based solution offers companies of all sizes access to sophisticated and innovative call center solutions quickly, at a cost of ownership far lower than traditional premise-based solutions, company officials said.

In November last year, Five9 announced the general availability of its second generation cloud computing platform, TMCnet reported.  The upgrade enables software assimilation with other programs and services in much the same way it’s used with Five9’s partners Salesforce, Netsuite, RightNow and Leads360.