What is an "infrastructure provider" (IP)?

From the current issue of ENR:

While Thames Water is promoting the project through its subsidiary Thames Tideway Tunnel Ltd. (TTT), the government and the Water Services Regulation Authority—known as OFWAT—have agreed to have the scheme procured by a stand-alone "infrastructure provider" (IP).

If anyone has additional information on this particular procurement, I would appreciate it (i.e., links to the procurement announcement, other applications of IPs, typical organization/financial structures, etc..)

http://enr.construction.com/infrastructure/environment/2014/0613-london-water-utility-seeks-investors-for-7billion-sewer-overflow-fix.asp