Nashville-based Petra Capital Partners has invested $6 million in a New Jersey company that designs and markets videoconferencing and other communications systems.

Petra's investment in York Telecom comes shortly after the firm said it had put $5 million into a Massachusetts HR software venture. As with that deal, Petra Managing Partner Mike Blackburn will join York's board.

York is the fourth investment from Petra Growth Fund II. York used some of the money to refinance debt and will put the rest toward funding its growth plan.

"We're excited about Petra Capital Partners' deep experience working with technology companies and the opportunity to work with their talented team of professionals," said Ron Gaboury, president and COO of York Telecom.