Seattle's DocuSign has reeled in $5 million in venture financing amid continued growth of its electronic signature product, TechFlash has learned. Existing investors -- including Frazier Technology Ventures, Ignition Partners, Sigma Partners and West River Capital -- participated in the deal which includes an option to raise an additional $10 million.

The company previously raised $12.4 million in the fall of 2007, bringing total funding at the time to about $30 million. After a series of restructurings and executive changes,  DocuSign appears to be on a solid growth path under the direction of former CourtLink CEO Matthew J. Schiltz.

Last quarter, the software-as-a-service company said that it had processed more than 25 million electronic signatures. It also recently noted that the business grew by 300 percent in the first quarter compared to the same period last year.

Just yesterday, DocuSign introduced the latest version of its product. New features include the ability to create a personalized electronic signature that matches the handwritten signature and additional support for document formats.

 “By focusing on cutting operational costs, accelerating revenue, and immediately impacting efficiency and profitability, our customers are driving tremendous business results for DocuSign," said founder and vice president of product strategy Tom Gonser in the release.

The DocuSign product is used in the financial services, travel and real estate industries, allowing organizations to accelerate the time it takes to complete a transaction and eliminating some of the waste associated with the transportation of paper documents. Customers include Re/Max, Prudential and Expedia.