Jive Software's new owner says it will close its Portland site rather than move to new offices when Jive's current lease expires at the end of September.

That marks the definitive end of a vital era in Portland tech.

Jive, which uses social networking technology to encourage business collaboration, was among the first of a new generation of Oregon tech companies focused on internet technologies rather than computer hardware, which had been the mainstay of the state's tech sector.

Jive struggled after going public in 2011, however. The company's growth slowed considerably, and it was unable to attract large organizations to its technology.

Under investor pressure, Jive sold last year to a little-known Texas company called Aurea for $462 million. Aurea then broke up the business, selling part of the company to a San Francisco firm called Lithium Technologies.

Jive once employed 300 or more on four stories of The Reserve building downtown, but many employees left after the company's sale. A former Jiver who had recently been in the office said no more than a few dozen remain.

After a "For Lease" sign went up outside the property, privately held Aurea confirmed it's closing up shop in Portland for good. Remaining Portland employees will work from home, the company said.

"Aurea subscribes to a 'future of work' philosophy, meaning we are a distributed, global, virtual organization that hires the best talent regardless of where they are," Aurea said in a statement Wednesday. "Given this organizational model, we do not plan to lease another office space in Portland."

Aurea said it will use Jive technology to encourage employees to collaborate while working from home. It declined to say how many employees remain in Portland.

Al Kennedy, with commercial real estate firm CBRE, said the four floors Jive occupies in a five-story office building called The Reserve are up for lease and will be available to new tenants Oct. 1.

-- Mike Rogoway; twitter: @rogoway; 503-294-7699