Business leaders gathered in Philadelphia Friday to pitch investors on plans to turn the region into an "energy hub" based on booming Marcellus Shale gas production.

It's hard to say exactly how it went, though, because most members of the news media were barred from the event. They hung around outside Drexel University's Creese Student Center, along with protesters who came to decry those plans to hinge the region's economy on fossil fuels.

The only journalists allowed inside were a Philadelphia Inquirer reporter and a freelancer representing the New York Times, according to a spokeswoman for the Greater Philadelphia Chamber of Commerce.

"It's by invitation-only because we think it's extremely important to have individuals that are empowered to make buying decisions meet each other here in Greater Philadelphia," said the chamber's CEO Rob Wonderling in a phone interview. "It is not a broad public policy event."

Wonderling is co-chairman of the Greater Philadelphia Energy Action Team, along with South Philadelphia refinery CEO Phil Rinaldi. The group – made up of regional business leaders, Marcellus Shale Coalition President David Spigelmyer and U.S. Rep. Patrick Meehan, R-Pa. – formed more than a year ago with the goal of expanding Philadelphia's role in the shale gas boom.

The "energy hub" vision includes plans for new pipelines to carry natural gas from wells in Northeast Pennsylvania to fuel new processing plants and refineries in this area that would turn that gas into building blocks for new products.

"We're hopeful that a year from now, introductions that were made today will bear fruit into commercial transactions," Wonderling said.

As event participants sat down to a networking breakfast Friday, dozens of protesters marched and chanted "no fracking hub," hoping their message could be heard inside.

"These companies cannot be trusted," said South Philadelphia resident Maria Kretschmann, who carried a sign reading, "Philadelphia is not for sale."

Kretschmann echoed others at the rally in her suspicion of the oil and gas industry, citing concerns about the impact of burning fossil fuels on public health and a warming planet.

"We don't want Philadelphia to go the old-fashioned, 19th and 20th century route of developing fossil fuels," said Tracey Carluccio with the Delaware Riverkeeper Network. "We want a green economy, and we want stable jobs for the future."

Carluccio said environmental groups are carefully planning their next steps and will likely target individual projects such as pipelines when they come up for state and federal permits.

Philadelphia will not become an energy hub overnight, and the timeline is unclear. However, discussion of the idea has accelerated in recent weeks. As Philadelphia debated an ultimately unsuccessful proposal to sell its gas utility to a private company, the Energy Action Team prepared for Friday's summit.

In an event packet provided by the Greater Philadelphia Chamber of Commerce, the Energy Action Team describes one of its goals to "identify barriers and work to mitigate them."