Some corporations are adopting social media for their employees with a twist — private social networks.

PriceWaterHouseCoopers is one, and it is using a rebranded version of the Jive social media tool, calling it Spark.

The goal of rolling out Spark online in April 2012 and now through an app, as well, was to increase adherence with the companies travel policies, to enhance collaboratons with travelers, and keep in touch with them on the road, says Gregory Whitaker, PwC solutions manager and chairman of the GBTA technology committee.

The most popular part of the tool is a Discussion section. “People love to talk about travel, about the program and travel apps,” Whitaker says.

The company can easily post discounts it’s negotiated, and publish all kinds of travel-related information that previously was scattered around the company’s website, Whitaker says.

Lots of companies are introducing these sorts of private social networks. They fear open social networks such as Facebook and Twitter for their employees out of privacy concerns, and because they don’t want to give competitors an edge by knowing where employees are traveling for business meetings.