HAUPPAUGE -- CosmoCom, a leader in Internet contact center technology, has received $15.3 million in mezzanine equity funding in what experts say is the largest-ever infusion of venture capital for a Long Island firm.

The majority of the funding comes from San Diego-based Science Applications International Corp., a Fortune 500 company that is the nation's largest employee-owned high-tech research and engineering firm. Several investors who took part in three previous capital rounds also participated in the recent fund drive, the last before CosmoCom heads public next year.

"That our existing investors all invested again shows they have a world of confidence" in CosmoCom, said company President and CEO Ari Sonesh. "It was our largest round of funding, and the largest on Long Island so far."

Jeffrey Bass, chairman of the Long Island Venture Group, verified that CosmoCom's funding set a local record: "It's just magnificent," he added. "It's a very significant amount of money."

The proceeds mark a milestone for the young CosmoCom, and will be used to grow the company in all areas, including sales, marketing and ongoing development to maintain its worldwide technology leadership position of its flagship product, CosmoCall Universe.

CosmoCom, which has been on a fast-track expansion since its founding in 1995, said the capital raised would be used for future expansion.

"This wasn't a debt situation. We're expanding very rapidly," said company spokesperson Wynne Fisher. Last week, the company added 10 employees to bring its staff tally to 60.

Sonesh would not disclose earnings, other than to say "it's in the millions" and that "each quarter we basically double our revenues.

"We have been building from the beginning with the intention to go public," he said. "There's no question we are the market leaders. We're not going public for the sake of going public, but to raise the capital necessary for expansion."

CosmoCom's development of the multiple award-winning CosmoCall Universe positions the company at the forefront of two important industry trends: live Internet customer care and distributed call centers.

The equity funding follows a September strategic agreement with Science Applications International -- known as SAIC -- that allows the California firm to resell CosmoCall Universe in the context of its system integration activities.

"The SAIC investment is a significant endorsement of CosmoCom's value proposition, enabling organizations to treat each customer individually, across all the ways each customer may now communicate, and to do this on a pure IP platform, said Bill Hills, a senior analyst in telecommunications software with Aberdeen Group, a Boston-based market research firm that specializes in e-business.

Founded in 1995 by former executives of Woodbury-based Comverse, CosmoCom counts Columbia University, the large Israeli ISP Surfree and Toronto-based InfoCast Corp. among its clients.

With annual revenues of $4.7 billion, SAIC and its subsidiaries have more than 38,000 employees with offices in more than 150 cities worldwide.