A fast-growing Petaluma telecom equipment company is sinking its roots deeper into Sonoma County with an expansion that could add new high-paying jobs to the economy.

Cyan, which currently occupies two floors of a building in the Redwood Business Center at Old Redwood Highway near Highway 101, is planning to expand into a second building in the same complex.

The company, founded in Petaluma in 2006 by four Telecom Valley pioneers, employs nearly 300 people in all, about two-thirds of them in Sonoma County. Most jobs, including engineering, finance and marketing positions, pay in the six figures.

The new building, at 1385 N. McDowell Blvd., is in the planning stages, according to property owners Basin Street Properties.

The 57,000-square-foot building is envisioned as three stories tall, with Cyan likely occupying the top two floors. The company has signed a long-term lease with Basin Street for the space.

Joe Cumello, chief marketing officer at Cyan, said the company is fast outgrowing its current headquarters.

"We're packed in like sardines now. We've made really good use of the space we're in, but we're jammed in there," he said.

The company, which went public in May and is traded on the New York Stock Exchange, is valued at about $460 million. It develops and sells software and equipment that help telephone companies, data centers and private network operators reduce the cost of moving data quickly across their networks.

The company had sales of $96 million in 2012, an increase from $40.5 million from 2011. It reached a milestone of 150 customers recently, Cumello said, for Blue Planet, its software-defined networking product.

Initial drawings for the new building show a pedestrian bridge between the third floors of the two adjacent buildings, creating a literal and figurative connection between the two Cyan spaces.

"It will be a nice flow for the organization. It will feel like a unified office environment," Cumello said. "It obviously helps us as the company grows."

The building should break ground soon, he said, and be finished next year.

He couldn't say how many new jobs may be created during the expansion. The new space hadn't been allocated to any specific department or specialty.

Petaluma city leaders hailed Cyan's expansion as a sign of resurgence of the city's place in the high-tech world. Petaluma was known as Telecom Valley during the 1990s in the early wave of the tech boom.

"We've been known as a high-technology area, but this brings it back to light," said Councilman Mike Harris. "There is a lot more momentum in the marketplace and people are starting to take notice."

Cyan has workers in San Francisco, Dallas, North Carolina, Canada, Japan, Hong Kong and Singapore.

"We have a philosophy that we will cultivate talent pools where there are talented people," Cumello said. "These are tech hubs where you find really good people. We believe Petaluma continues to be an important part of our employee base."

Cyan's revenue for the second quarter of 2013 grew 37 percent year-over-year to a record $31.7 million, up from $23.1 million in the second quarter of 2012, and up 20 percent from $26.3 million for the previous quarter.

Net loss for the quarter was $9.1 million, compared to a net loss of $1.5 million in the same period last year and a net loss of $9.4 million in the first quarter of 2013, according to the company.