UNIONDALE, N.Y.--(BUSINESS WIRE)--EC Infosystems, a leader in Electronic Data Interchange (EDI) and Billing/Customer Information Solutions (CIS) for clients in the deregulated energy industry, today announced that Chief Energy has renewed its contract with EC Infosystems for the company’s integrated EDI and CIS/Billing solution. Chief Energy is an Energy Service Company (ESCO) registered with the New York State Public Service Commission [NYSPSC] that supplies natural gas and electricity within