The agreement, which comes into effect immediately, will see ITNet provide consultancy, change management and application services in addition to managing the data and voice networks, 50 servers, IT helpdesk and provide desktop support for 1,900 PCs.
The outsourcer will migrate legacy applications from the council's Fujitsu mainframe system and implement a new Council Tax and benefits system using its One Gov Direct service.
It will use the mySap Business Suite to replace more than 20 mainframe legacy systems, while SAP’s Enterprise Portal technology will be used to upgrade the council's intranet and website.
ITNet has been heavily criticised for problems with revenue and benefits outsourcing contracts at London councils such of Hackney and Islington. This week it received a £2m payment from Islington for the early termination of a contract. However, Richmond upon Thames believes its deal will benefit local residents.
"We are confident that ITNet will make a visible difference to the e-government aspirations of the council,” said Mike Gravatt, Richmond's assistant director of finance.