Israeli startup Conduit is on the verge of a huge exit: It is negotiating a sale estimated at over a billion dollars. Among the potential buyers mentioned are such giants as Microsoft and Google.

Conduit, considered one of the most promising high tech companies in Israel, was founded in 2005 and creates platforms for browser toolbars and applications. If the deal comes off, it would be the biggest sale of an Internet firm in Israeli history.

Conduit’s products allow anyone, including small firms, to create personalized toolbars, and clients range from small stores to the NBA and singer Rihanna.

The company has raised only $9.5 million, in 2005 and 2008, and is considered profitable. It had revenues of about $100 million in 2009 and $300 million in 2010. Conduit has 250 employees in its center in Nes Tziona, 100 of whom were hired in the last year.

Shaul Olmert, the chief marketing officer, refused to comment on a sale. “We have tried to build an Internet company on an international scale in Israel,” he said. He added the company was committed to Israel and would continue to grow here.

In the past, Conduit turned down a buyout offer of $100 million.

The company has 230 million users of its products, half the number of Facebook users, and more than LinkedIn and Twitter, said Olmert. He said Conduit is also more profitable than those firms.

The three founders, CEO and chairman Ronen Shilo, chief technology Officer Dror Erez and chief operating officer Gaby Bilczyk, own 48% of the company, and they will take home the biggest share of the money. The Yozma venture capital fund invested $1.5 million in the firm in 2005 and owns a 10% share. Benchmark Capital holds 21% after investing $8.5 million in 2008.